EnC - More attribute edit tests

[davidwengier]

Looks like I missed tests for some things, so need to add some (and fix anything if they fail, obv)

• Need syntax editing tests for:
  • Events: EnC - add tests for attributes on events #54787
• Need emit tests for:
  • Events: EnC - add tests for attributes on events #54787
  • Method parameters: Emit attribute changes for parameters #54835
  • Method return types: EnC: Include added types in changed types of emit result #55099
  • Delegates: Add more attribute tests for more things #55881
  • Delegate parameters: EnC: Include added types in changed types of emit result #55099
  • Delegate return types: EnC: Include added types in changed types of emit result #55099
  • Properties: Add more attribute tests for more things #55881
  • Fields: Add more attribute tests for more things #55881
  • Types: Add more attribute tests for more things #55881
  • Generic Types: N/A, not supported
  • Enum members: Add more attribute tests for more things #55881

[tmat]

We should have tests for attribute updates on all kinds of symbols. Our tests are grouped by symbol kind and each test group should test modifier and attribute edits.