No engine work

* Use Microsoft.NET.Sdk.WindowsDesktop for XAML projects

* Move "is telemetry allowed" flag to DiagnosticAnalyzerInfoCache

* Clean up DiagnosticService

* Fixes

* Remove analyzer exception telemetry reporting.

* Remove reporting analyzer exceptions from SupportedDiagnostics.

The diagnostics will be reported when the compiler runs the analyzer on the compilation.

* Remove unused parameter

* Clean up analyzer telemetry reporting.

* Test fixes

* Feedback

* Insert correct `WithNullableContext` binder into the binder chain to ensure speculative models return correct information based on speuclation location.

* Refactor Nullable context options to rely on an enum instead of two bools.
Break out the BuckStopsHereBinder's code to allow sharing.
Fix binder ordering issue for TryGetSpeculativeSemanticModelForMethodBody.

* Make NullableContextState.State a byte for space.

Fix #40499

Co-Authored-By: NJoey Robichaud <joseph.robichaud@microsoft.com>

removed most of the last commit (handling declarators) since they aren't discards from the compilers view. Kept the tests around and tweaked them so they now check that nothing is classified in these cases.