Support the user preference for trailing-new-lines when moving types.

Fix serialization of decimals

Take a screenshot when an Assert fails

Warn if we're offering a Coalesce Expression inside an ExpressionOfT.

return null session if RemoteHost is not reachable

Add a completion provider that suggests tuple names

Properly handle adding multiple usings when there is a banner at the top of the file.

This behavior is controlled in C# with `BinderFlags.IgnoreCorLibraryDuplicatedTypes`, and in VB with an internal compilation option (use `WithIgnoreCorLibraryDuplicatedTypes`).

* do perf tests on other branches

* fix branc hname

* use branchName

renamed CreateSession to TryCreateSession and added some doc comment.

Fixes #14882
Fixes #13840
Fixes #13915

Standardize on SymbolInfo.None vs. default(SymbolInfo)

Check the model.TriggerSnapshot to determine if we're after a dot.

Fix the SyntaxPath always true conditions

Fixes #16565

Handle errors in cleanup_perf.ps1

Remove duplication in SynthesizedLocal

I'm not sure if this is really better, but it is consistent with the rest of the file.

Improve the locations where the Change-Signature refactoring is offered.

Remove a few unnecessary CCI interfaces

Fixes #9261.

Fixes #12052

Capture the name of the currently executing test, and use that to name screenshot files. We do this with a simple type that derives from xUnit's `BeforeAfterTestAttribute`.

Also, split some `AppDomain` event hookups out of the `VisualStudioInstanceFactory` static constructor; these belong in the instance constructor.