Fix focus of items
Fix accelerator key duplication
Narrator reads the datagrid correctly

* removed IEditorClassificationService that is marked obsolete since 2017 and bunch of other code that only existed for the IEditorClassificationService.

according to vso, only F# still has dependency so I talked to them to move to new API (IClassificationService) - https://devdiv.visualstudio.com/DevDiv/_git/DotNet-Source-Build-Tarball?path=%2Fsrc%2Ffsharp%2Fvsintegration%2Fsrc%2FFSharp.Editor%2FClassification%2FColorizationService.fs&version=GBmaster

and a bunch of clean up and move code that has no dependency to the editor to lower layers so that I can consume in razor scenario.

* added shim project for FSharp that has internal visible to FSharp editor

* merged https://github.com/dotnet/roslyn/pull/31941

* addressing PR feedback

* moved some type (such as DocumentSpan, ClassifiedSpan and etc) back to where fsharp has IVT to.

can't move those since partner team is using them and they don't have IVT to workspace layer for some reasons.

also, have put the IEditorClassificationService back and add a proxy in FSharp External Access so that it can still work until they remove all IVT.

Merge dev16.1-preview1 to master

We previously decided to remove IFromIndexOperation in favor of using an IUnaryOperation to represent the ^ syntax in C#, but did not have time to remove the interface completely. This PR finishes the change.

Run CI on dev16.1-preview1 branches

Do not return null task In RemoveHostClientExtensions

Track l-values in conditional operator
Assignment to ref variable produces safety warnings

* Analyze nullability in script initializer

* C# 8 for scripts for now

* nullable context script test

* extra null check

* added possibility to set c# Language Version on ScriptOptions

* adjust tests

* added ScriptOptionsTests for C# lang version

* adapted tests after rebase

* code review changes

* fixed test names & resx CDATA

* changed the ScriptOptions.WithLanguageVersion error message text and moved it to ScriptingResources.resx

* Update CSharpScriptingResources.Designer.cs

correctly.

Fixes
https://devdiv.visualstudio.com/_workitems/edit/794055?fullScreen=True

Fixes https://devdiv.visualstudio.com/_workitems/edit/794061

Move checks in build.ps1 into try/catch block

Co-Authored-By: Nryzngard <ryzngard@live.com>

Update infrastructure for 16.1 preview1

* made light bulb to check workspace status service

* rename field name

* addressing PR feedbacks

* LB created more implementation than I needed

* add tracking issues.

* Fixes 33603 and 33623

* Respond to feedback

* Fix spelling/random characters
Co-Authored-By: Nchborl <chborl@users.noreply.github.com>

* Use IsEmpty property
Co-Authored-By: Nchborl <chborl@users.noreply.github.com>

* remove unneeded null check

* Configure await false
Co-Authored-By: Nchborl <chborl@users.noreply.github.com>

* refactor null check
Co-Authored-By: Nchborl <chborl@users.noreply.github.com>

* Respond to feedback and refactor

* Wrap long lines

* Update test comments
Co-Authored-By: Nchborl <chborl@users.noreply.github.com>

* Change .AsImmutableOrNull to .ToImmutableAndFree
Co-Authored-By: Nchborl <chborl@users.noreply.github.com>

* Fix test doc comments

* Apply suggestions from code review

Update doc comment
Co-Authored-By: Nchborl <chborl@users.noreply.github.com>

* Fixes #34176

* Fix test name

* Update tests - WIP

* Fix conditional

* Improve conditional

* add tests and check for caret before string

* Move EnC debug information reading to Features.

Encapsulate the logic in EditAndContinueMethodDebugInfoReader.

Cleanup project and solution

Update AnalyzerRunner launch settings

Filter out additive classifications in EditorClassifier

Handle ChangeDocumentInfo in the VS workspace and update Rename File To Match Type

Fix GetOpenDocumentInCurrentContextWithChanges with linked files

Append xml doc comment for ILocalSymbol.IsFunctionValue

* Verify 31584
* Verify 32463
* Verify 26696

Typo fix

Disable rename tracking when replacing with discard

* Revert "Revert "Interactive projects refactoring (#29069)""

This reverts commit e0a8124f.

* Fix bad merge