fixes #38207

* Add CodeAction Type

Adds skeleton on a new CodeActionType and allows codeActionProvider to return either `Command`s or `CodeAction`s

Move proposed CodeAction API to proposed and try using it in TS

Split CodeAction into quickfix and refactoring classes

Update proposed interface

Update for new API

Adding basic docs

* Support workspace edits and text edits in codeactions

* Remove placeholders

* Resolving conflicts and making PR suggested changes

* Fix quick fix test

* Revert change to only use `CodeAction` instead of `CodeAction | Command` in modes since this will break `vscode.executeCodeActionProvider`