Updated city name in test file

Intellisense cannot be shown when the caret is between two dots

* Track nullability of static fields

* PR feedback

* Fix tests

* PR feedback

* Misc.

Fix formatting tests

Avoid a lambda allocation when accessing a cache in a hotpath.

Updated dotnet-format install instructions

Resaon for the change should be clear in the diff

Do not offer to remove redundant assignment if it is not parented by …

Fix documentation tests

- Added instructions for installing from NuGet.org

The reason for this should be clear in the change.

Co-Authored-By: NCyrusNajmabadi <cyrus.najmabadi@gmail.com>

Co-Authored-By: NCyrusNajmabadi <cyrus.najmabadi@gmail.com>

Co-Authored-By: NCyrusNajmabadi <cyrus.najmabadi@gmail.com>

Fix up support for changing rule set files through the Solution Explorer 

* Fix naming, remove help button, let the UI has a default selected destination

* Add comments

* remote question mark from warning dialog

Merge dev16.0-preview3 to master

Remove unnecessary test hooks

Disable integration tests with <95% reliability

Bail out for error types from IDE0058 analyzer (unused expression value)

The AnalyzersCommandHandler was still trying to call GetHostProject
to find the host project as a way to directly grab the rule set file
to process that. That was deprecated but we hadn't fixed it up yet.

The fix is to re-thread through a way to get to the rule set. The
"ownership" of a rule set file (if one exists for a project) is owned
by the VisualStudioProjectOptionsProcessor, so we now need a way to jump
to that directly from any project so another map is added to the
VisualStudioWorkspaceImpl. That map is unfortunate -- the
OptionsProcessor is really something that should be private to the
project system itself and shouldn't be grabbable by any random code.

Fixes https://devdiv.visualstudio.com/DevDiv/_workitems/edit/779916
Completes task https://devdiv.visualstudio.com/DevDiv/_workitems/edit/698029

* Enable LinkedFileDiffMergingEditorTests.TestCodeActionPreviewAndApply test

* Enable InteractivePasteCommandhandlerTests.PasteCommandWithOutInteractiveFormat test

* Updated LinkedFileDiffMergingEditorTests with PR feedback
Co-Authored-By: NJoeRobich <joseph.robichaud@microsoft.com>