Update event payload to send JSON object

[smithclay]

Description: Sends JSON in additional_info instead of a JSON string and normalizes map fields to string key/value pairs.

Example event from k8sobjectsreceiver:

      {
         "resource":";k8s.resource.name=events;event.domain=k8s;event.name=k8s-informer-hlasalesdemo1.17d8b16917e4bc96;watch-type=MODIFIED;deprecatedLastTimestamp=2024-06-13T22:39:31Z;kind=Event;apiVersion=events.k8s.io/v1;reason=ScalingReplicaSet;note=(combined from similar events): Scaled down replica set k8s-informer-hlasalesdemo1-f6d787558 to 0 from 1;type=Normal;deprecatedFirstTimestamp=2024-06-13T22:38:42Z;creationTimestamp=2024-06-13T22:38:42Z;name=k8s-informer-hlasalesdemo1.17d8b16917e4bc96;namespace=servicenow;uid=0d84ac74-444d-4a86-b011-8632feaed2c0;resourceVersion=28612",
         "node":"",
         "severity":"5",
         "type":"",
         "description":"{\"object\":{\"apiVersion\":\"events.k8s.io/v1\",\"deprecatedCount\":3,\"deprecatedFirstTimestamp\":\"2024-06-13T22:38:42Z\",\"deprecatedLastTimestamp\":\"2024-06-13T22:39:31Z\",\"deprecatedSource\":{\"component\":\"deployment-controller\"},\"eventTime\":null,\"kind\":\"Event\",\"metadata\":{\"creationTimestamp\":\"2024-06-13T22:38:42Z\",\"managedFields\":[{\"apiVersion\":\"v1\",\"fieldsType\":\"FieldsV1\",\"fieldsV1\":{\"f:count\":{},\"f:firstTimestamp\":{},\"f:involvedObject\":{},\"f:lastTimestamp\":{},\"f:message\":{},\"f:reason\":{},\"f:source\":{\"f:component\":{}},\"f:type\":{}},\"manager\":\"kube-controller-manager\",\"operation\":\"Update\",\"time\":\"2024-06-13T22:39:31Z\"}],\"name\":\"k8s-informer-hlasalesdemo1.17d8b16917e4bc96\",\"namespace\":\"servicenow\",\"resourceVersion\":\"28612\",\"uid\":\"0d84ac74-444d-4a86-b011-8632feaed2c0\"},\"note\":\"(combined from similar events): Scaled down replica set k8s-informer-hlasalesdemo1-f6d787558 to 0 from 1\",\"reason\":\"ScalingReplicaSet\",\"regarding\":{\"apiVersion\":\"apps/v1\",\"kind\":\"Deployment\",\"name\":\"k8s-informer-hlasalesdemo1\",\"namespace\":\"servicenow\",\"resourceVersion\":\"30426857\",\"uid\":\"77e5c426-44fd-4462-b028-c02d9beb1353\"},\"type\":\"Normal\"},\"type\":\"MODIFIED\"}",
         "time_of_event":"1970-01-01 00:00:00",
         "additional_info":{
            "apiVersion":"events.k8s.io/v1",
            "creationTimestamp":"2024-06-13T22:38:42Z",
            "deprecatedFirstTimestamp":"2024-06-13T22:38:42Z",
            "deprecatedLastTimestamp":"2024-06-13T22:39:31Z",
            "deprecatedSource_component":"deployment-controller",
            "event_domain":"k8s",
            "event_name":"k8s-informer-hlasalesdemo1.17d8b16917e4bc96",
            "k8s_resource_name":"events",
            "kind":"Event",
            "metadata_creationTimestamp":"2024-06-13T22:38:42Z",
            "metadata_name":"k8s-informer-hlasalesdemo1.17d8b16917e4bc96",
            "metadata_namespace":"servicenow",
            "metadata_resourceVersion":"28612",
            "metadata_uid":"0d84ac74-444d-4a86-b011-8632feaed2c0",
            "name":"k8s-informer-hlasalesdemo1.17d8b16917e4bc96",
            "namespace":"servicenow",
            "note":"(combined from similar events): Scaled down replica set k8s-informer-hlasalesdemo1-f6d787558 to 0 from 1",
            "reason":"ScalingReplicaSet",
            "regarding_apiVersion":"apps/v1",
            "regarding_kind":"Deployment",
            "regarding_name":"k8s-informer-hlasalesdemo1",
            "regarding_namespace":"servicenow",
            "regarding_resourceVersion":"30426857",
            "regarding_uid":"77e5c426-44fd-4462-b028-c02d9beb1353",
            "resourceVersion":"28612",
            "type":"Normal",
            "uid":"0d84ac74-444d-4a86-b011-8632feaed2c0",
            "watch-type":"MODIFIED"
         },
         "source":"sn-otel-collector"
      }