XDR-15964 add detection_sources to incident (#457)

Epic: https://cisco-sbg.atlassian.net/browse/XDR-15686
Closes: https://cisco-sbg.atlassian.net/browse/XDR-15694

Summary: Adds optional `detection_sources` field to the Incident object. `detection_sources` differs from `source` in that `source` is the promoter of the incident, whereas `detection_sources` is the a set of aggregated sources of detections, such as sightings, that are found in the incident. This is meant be a searchable field on the Incidents List in the UI (see the epic above) and as such must be available via Lucene query. 

Local generative and testing steps:
1. Ran `lein doc` and commited results
2. Ran `lein test`, which passed

doc/json/actor.json

@@ -26,7 +26,7 @@
   "motivation" : "Ego",
   "planning_and_operational_support" : "string",
   "revision" : 10,
-  "schema_version" : "1.3.20",
+  "schema_version" : "1.3.21",
   "short_description" : "string",
   "sophistication" : "Aspirant",
   "source" : "string",

doc/json/asset.json

@@ -12,7 +12,7 @@
   "id" : "string",
   "language" : "string",
   "revision" : 10,
-  "schema_version" : "1.3.20",
+  "schema_version" : "1.3.21",
   "short_description" : "string",
   "source" : "string",
   "source_uri" : "string",

doc/json/asset_mapping.json

@@ -17,7 +17,7 @@
     "value" : "1.2.3.4"
   },
   "revision" : 10,
-  "schema_version" : "1.3.20",
+  "schema_version" : "1.3.21",
   "source" : "string",
   "source_uri" : "string",
   "specificity" : "Low",

doc/json/asset_properties.json

@@ -15,7 +15,7 @@
     "value" : "string"
   } ],
   "revision" : 10,
-  "schema_version" : "1.3.20",
+  "schema_version" : "1.3.21",
   "source" : "string",
   "source_uri" : "string",
   "timestamp" : "2016-01-01T01:01:01.000Z",

doc/json/attack_pattern.json

@@ -16,7 +16,7 @@
   } ],
   "language" : "string",
   "revision" : 10,
-  "schema_version" : "1.3.20",
+  "schema_version" : "1.3.21",
   "short_description" : "string",
   "source" : "string",
   "source_uri" : "string",

doc/json/bundle.json

@@ -28,7 +28,7 @@
     "motivation" : "Ego",
     "planning_and_operational_support" : "string",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "short_description" : "string",
     "sophistication" : "Aspirant",
     "source" : "string",
@@ -62,7 +62,7 @@
       "value" : "1.2.3.4"
     },
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "source" : "string",
     "source_uri" : "string",
     "specificity" : "Low",
@@ -92,7 +92,7 @@
       "value" : "string"
     } ],
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "source" : "string",
     "source_uri" : "string",
     "timestamp" : "2016-01-01T01:01:01.000Z",
@@ -119,7 +119,7 @@
     "id" : "string",
     "language" : "string",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "short_description" : "string",
     "source" : "string",
     "source_uri" : "string",
@@ -151,7 +151,7 @@
     } ],
     "language" : "string",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "short_description" : "string",
     "source" : "string",
     "source_uri" : "string",
@@ -185,7 +185,7 @@
     "language" : "string",
     "names" : [ "string" ],
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "short_description" : "string",
     "source" : "string",
     "source_uri" : "string",
@@ -259,7 +259,7 @@
       "source" : "string"
     } ],
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "short_description" : "string",
     "source" : "string",
     "source_uri" : "string",
@@ -297,7 +297,7 @@
     "revision" : 10,
     "row_count" : 10,
     "rows" : [ [ "anything" ] ],
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "short_description" : "string",
     "source" : "string",
     "source_uri" : "string",
@@ -335,7 +335,7 @@
     "language" : "string",
     "reason" : "string",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "source" : "string",
     "source_uri" : "string",
     "timestamp" : "2016-01-01T01:01:01.000Z",
@@ -366,7 +366,7 @@
     },
     "language" : "string",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "source" : "string",
     "source_uri" : "string",
     "timestamp" : "2016-01-01T01:01:01.000Z",
@@ -383,6 +383,7 @@
     "categories" : [ "Attrition" ],
     "confidence" : "High",
     "description" : "string",
+    "detection_sources" : [ "string" ],
     "discovery_method" : "Agent Disclosure",
     "external_ids" : [ "string" ],
     "external_references" : [ {
@@ -408,7 +409,7 @@
     },
     "promotion_method" : "Automated",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "scores" : {
       "asset" : 10.0
     },
@@ -451,7 +452,7 @@
     "negate" : true,
     "producer" : "string",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "severity" : "Critical",
     "short_description" : "string",
     "source" : "string",
@@ -500,7 +501,7 @@
     "reason" : "string",
     "reason_uri" : "string",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "severity" : "Critical",
     "source" : "string",
     "source_uri" : "string",
@@ -533,7 +534,7 @@
     "labels" : [ "adware" ],
     "language" : "string",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "short_description" : "string",
     "source" : "string",
     "source_uri" : "string",
@@ -563,7 +564,7 @@
       "entity_type" : "string"
     } ],
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "source" : "string",
     "source_uri" : "string",
     "timestamp" : "2016-01-01T01:01:01.000Z",
@@ -585,7 +586,7 @@
     "language" : "string",
     "relationship_type" : "attributed-to",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "short_description" : "string",
     "source" : "string",
     "source_ref" : "string",
@@ -597,7 +598,7 @@
     "type" : "relationship"
   } ],
   "revision" : 10,
-  "schema_version" : "1.3.20",
+  "schema_version" : "1.3.21",
   "short_description" : "string",
   "sighting_refs" : [ "string" ],
   "sightings" : [ {
@@ -865,7 +866,7 @@
     } ],
     "resolution" : "detected",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "sensor" : "endpoint",
     "sensor_coordinates" : {
       "observables" : [ {
@@ -912,7 +913,7 @@
     "id" : "string",
     "language" : "string",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "short_description" : "string",
     "source" : "string",
     "source_uri" : "string",
@@ -958,7 +959,7 @@
     "labels" : [ "credential-exploitation" ],
     "language" : "string",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "short_description" : "string",
     "source" : "string",
     "source_uri" : "string",
@@ -1099,7 +1100,7 @@
     "last_modified_date" : "2016-01-01T01:01:01.000Z",
     "published_date" : "2016-01-01T01:01:01.000Z",
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "short_description" : "string",
     "source" : "string",
     "source_uri" : "string",
@@ -1180,7 +1181,7 @@
       "strategy" : "Attack Surface Reduction"
     } ],
     "revision" : 10,
-    "schema_version" : "1.3.20",
+    "schema_version" : "1.3.21",
     "short_description" : "string",
     "source" : "string",
     "source_uri" : "string",

doc/json/campaign.json

@@ -19,7 +19,7 @@
   "language" : "string",
   "names" : [ "string" ],
   "revision" : 10,
-  "schema_version" : "1.3.20",
+  "schema_version" : "1.3.21",
   "short_description" : "string",
   "source" : "string",
   "source_uri" : "string",