[flake8-pyi] Make PYI019 autofixable for .py files in preview mode as well as stubs

[AlexWaygood]

(This PR is stacked on top of #15885 and #15888; review those first.)

Summary

Now that this is a bindings-based rule, I think the autofix can be safely applied to .py files as well as stubs. All we need to do is search the method body for references we might need to replace as well as searching the method header.

@InSyncWithFoo mentioned in #15821 that there might be some edge cases to do with stringized type expressions where this wouldn't work well. I've made the rule unfixable in these edge cases by bailing out of the fix if we see that any references in the source code do not exactly match the original TypeVar name.

Test Plan

New snippets added to the fixture files.

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

ℹ️ ecosystem check detected linter changes. (+0 -0 violations, +26 -0 fixes in 3 projects; 52 projects unchanged)

apache/superset (+0 -0 violations, +2 -0 fixes)

ruff check --no-cache --exit-zero --ignore RUF9 --no-fix --output-format concise --preview --select ALL

- superset/sql/parse.py:167:21: PYI019 Use `Self` instead of custom TypeVar `TBaseSQLStatement`
+ superset/sql/parse.py:167:21: PYI019 [*] Use `Self` instead of custom TypeVar `TBaseSQLStatement`

rotki/rotki (+0 -0 violations, +20 -0 fixes)

ruff check --no-cache --exit-zero --ignore RUF9 --no-fix --output-format concise --preview

- rotkehlchen/db/filtering.py:1138:13: PYI019 Use `Self` instead of custom TypeVar `T_EthSTakingFilterQ`
+ rotkehlchen/db/filtering.py:1138:13: PYI019 [*] Use `Self` instead of custom TypeVar `T_EthSTakingFilterQ`
- rotkehlchen/db/filtering.py:373:15: PYI019 Use `Self` instead of custom TypeVar `T_FilterQ`
+ rotkehlchen/db/filtering.py:373:15: PYI019 [*] Use `Self` instead of custom TypeVar `T_FilterQ`
- rotkehlchen/db/filtering.py:866:13: PYI019 Use `Self` instead of custom TypeVar `T_HistoryBaseEntryFilterQ`
+ rotkehlchen/db/filtering.py:866:13: PYI019 [*] Use `Self` instead of custom TypeVar `T_HistoryBaseEntryFilterQ`
- rotkehlchen/history/events/structures/base.py:372:39: PYI019 Use `Self` instead of custom TypeVar `T`
+ rotkehlchen/history/events/structures/base.py:372:39: PYI019 [*] Use `Self` instead of custom TypeVar `T`
- rotkehlchen/utils/mixins/enums.py:101:20: PYI019 Use `Self` instead of custom TypeVar `S`
+ rotkehlchen/utils/mixins/enums.py:101:20: PYI019 [*] Use `Self` instead of custom TypeVar `S`
- rotkehlchen/utils/mixins/enums.py:126:20: PYI019 Use `Self` instead of custom TypeVar `S`
+ rotkehlchen/utils/mixins/enums.py:126:20: PYI019 [*] Use `Self` instead of custom TypeVar `S`
- rotkehlchen/utils/mixins/enums.py:12:16: PYI019 Use `Self` instead of custom TypeVar `T`
+ rotkehlchen/utils/mixins/enums.py:12:16: PYI019 [*] Use `Self` instead of custom TypeVar `T`
- rotkehlchen/utils/mixins/enums.py:151:28: PYI019 Use `Self` instead of custom TypeVar `D`
+ rotkehlchen/utils/mixins/enums.py:151:28: PYI019 [*] Use `Self` instead of custom TypeVar `D`
- rotkehlchen/utils/mixins/enums.py:172:28: PYI019 Use `Self` instead of custom TypeVar `D`
+ rotkehlchen/utils/mixins/enums.py:172:28: PYI019 [*] Use `Self` instead of custom TypeVar `D`
- rotkehlchen/utils/mixins/enums.py:77:20: PYI019 Use `Self` instead of custom TypeVar `S`
+ rotkehlchen/utils/mixins/enums.py:77:20: PYI019 [*] Use `Self` instead of custom TypeVar `S`

zulip/zulip (+0 -0 violations, +4 -0 fixes)

ruff check --no-cache --exit-zero --ignore RUF9 --no-fix --output-format concise --preview --select ALL

- zerver/data_import/slack.py:109:18: PYI019 Use `Self` instead of custom TypeVar `SlackBotEmailT`
+ zerver/data_import/slack.py:109:18: PYI019 [*] Use `Self` instead of custom TypeVar `SlackBotEmailT`
- zerver/lib/thumbnail.py:55:20: PYI019 Use `Self` instead of custom TypeVar `T`
+ zerver/lib/thumbnail.py:55:20: PYI019 [*] Use `Self` instead of custom TypeVar `T`

Changes by rule (1 rules affected)

code	total	+ violation	- violation	+ fix	- fix
PYI019	26	0	0	26	0