- Making Project.Language check case sensitive

will result in a linked doc language being “TypeScript” when the original
doc language was “C#”. This is because GetLinkedDocumentIds() and GetRelatedDocumentIds()
retrieve documents based on the file path and both of the ContainedDocuments will have
the same path (ex: LoginView.cshtml) with different documentIds.

This leads to NullReferenceExceptions in Salsa ContainedDocument scenarios

Fix:
- Change GetRelatedDocumentIds(DocumentId documentId) and GetLinkedDocumentIds() to filter documents by language
- Add GetDocumentGroupKey method to AbstractRoslynTableDataSource and use this instead of GetRelatedDocumentIds for the aggregated key

Ensure that suppression state for build diagnostics shows up as active instead of <blank>, and build diagnostics are not suppressible from error list, i.e. "Suppress" menu does not show up in the error list.

Fixes VSO [#164642](https://devdiv.visualstudio.com/DefaultCollection/DevDiv/_workitems#_a=edit&id=164642)

also added test for those cases

Fix unit test failures and address PR feedback: IDE diagnostic service now reports source suppressed diagnostics. So add an optional flag to the diagnostic analyzer service APIs to control whether or not to return suppressed diagnostics, and update the test framework to thread this flag.

This change adds a new "Suppression State" column to the error list and adds context menus to the error list for bulk suppression. A command handler is added to register these commands. VisualStudioBaseDiagnosticListTable and its subtypes have been modified to handle and populate the new column in the error list.

NOTE: The new error list column, context menu commands and the command handler for error list context menus will be moved to the VS shell layer so that it can plug into FxCop diagnostic provider as well.

now user has a easy way to see just errors from build. the content should be exactly same as what output build window shows.

this change set also includes several misc changes such as adding support for error source and build tool.

removed unused using and use ProjectGuid from editor rather than defining our own since we have new bits now

editor team has refactored thier table control APIs

we will move away from IVsHierarchy and start to use ProjectIdGuid instead.

This ensures that the url displayed in the tooltip is more human readable.

Display a tooltip containing url destination for hyperlinks in the error list and light bulb preview pane UIs.

Also use full fidelity (i.e. substituted)  error message in the search query in the case of hyperlinks that redirect to bing search so that we can present more relevant search results.

now, error list will have column (which is off by default) that shows source of each errors in a
format "assembly name" for analyzers node. and "assembly name" [vsix name] for vsix

previously we reported actual project (active context project in case of project k/shared project) to error list. this should let error list to only show errors for one specific project when current project filtering is set.

but right now error list uses IVsHierarchy of project k/shared project rather than active context. so for RC, we will do that. that means for project k/shared project, we will show errors for all context (multiple projects)  when the filtering is set.

for RTM, we will resolve design issue of what "Current Project" filtering means for error list.

when error list data source and diagnostic service gets out of sync, let error list itself request a fix up rather than waiting diagnostic service to do so.

due to async nature of error list and diagnostic that doesnt share versioning, intermidiate out of sync can happen.

other ones such as build will have minimum length of 0 for squiggles since they are not updated as your types. minimum length of 1 for such squiggle just makes it look like staled squiggles.