* Add AB tests for code cleanup
revert the text change of Code_cleanup_is_not_configured, as the new text is not translated
Only SettingIsAlreadyUpdatedByExperiment to ture for Group B; always show gold bar if user setting is changed in AB test

These are missing languages which production team delivered today.

* remove usings when format document

* sort usings when format document

* add code fix

* hack fix for the issue with apply multiple changes.

* refactoring

* 3 changes

1. put open file editorconfig change tracking back
2. handle open file leaking when solution close with files opened case
3. don't share locks between editorconfig events and roslyn events

* skip the 'Remove unused variable' when format document

* changed code fix part to use "fix all" and only fixes P1 list rather than fix everything in the document. also not apply changes to buffer until everything is done rather than doing it per fix.

* made undo experience better

* add expression body as one of fix to offer

* add code fix options in format document settings

* add hidden box IsCodeCleanupConfiguredCheckBox to track if the user ever configured the code cleanup

* clean up

* fix some tests

* disable a test temporarily

* PR comments

* refactoring

* Revert "3 changes"

This reverts commit 7e0fd53f02a0e20d063440b3cce5569e51e71afc.

* PR comments

* PR comments

* renaming

* bug fixing

* PR comments

* refactoring

* refactoring

* refactoring

* refactoring

* Make ICodeCleanupService extend ILanguageService

* refactoring

* refactoring

* fix deadlock, call Format inside CodeCleanupService

* rename async methods

* PR comments

* move files under features

* PR comments

* PR comments

* Never Show this again will never show the code cleanup info bar for this user.

* rename

* use ImmutableArray