Multiple integration test failures from flakiness

[JoeRobich]

As reported in #4852 (comment)

The first failure is because OmnisharpProjectDiagnosticStatus.message.ProjectFilePath was null

  1) OmnisharpReferenceProvider: sln with several csproj's
       "before all" hook for "Returns the reference without declaration":
     Uncaught TypeError: Cannot read property 'replace' of null
      at t.call [as _next] (src/observers/BackgroundWorkStatusBarObserver.ts:17:74)
      at t.__tryOrUnsub (node_modules/rxjs/_esm5/internal/Subscriber.js:192:16)
      at t.next (node_modules/rxjs/_esm5/internal/Subscriber.js:130:22)
      at t._next (node_modules/rxjs/_esm5/internal/Subscriber.js:76:26)
      at t.next (node_modules/rxjs/_esm5/internal/Subscriber.js:53:18)
      at t.next (node_modules/rxjs/_esm5/internal/Subject.js:47:25)
      at t.EventStream.post (src/EventStream.ts:16:19)
      at EventEmitter.<anonymous> (src/omnisharp/server.ts:307:30)
      at k._fireEvent (src/omnisharp/server.ts:248:24)
      at k._handleEventPacket (src/omnisharp/server.ts:738:18)
      at k._onLineReceived (src/omnisharp/server.ts:703:22)
      at Interface._onLine (readline.js:337:10)
      at Interface._normalWrite (readline.js:482:12)
      at Socket.ondata (readline.js:194:10)
      at addChunk (internal/streams/readable.js:309:12)
      at readableAddChunk (internal/streams/readable.js:284:9)
      at Socket.Readable.push (internal/streams/readable.js:223:10)
      at Pipe.onStreamRead (internal/stream_base_commons.js:188:23)


  2) OmnisharpReferenceProvider: sln with several csproj's
       "before all" hook for "Returns the reference without declaration":
     Error: done() called multiple times in hook <OmnisharpReferenceProvider: sln with several csproj's "before all" hook for "Returns the reference without declaration"> of file /home/runner/work/omnisharp-vscode/omnisharp-vscode/out/test/integrationTests/referenceProvider.test.js
      at processTicksAndRejections (internal/process/task_queues.js:93:5)

[JoeRobich]

Additional flaky tests from #4856

Error: 2 tests failed.
  4 pending

  2 failing
  1) ReAnalyze: sln with several csproj's
       When re-analyze of all projects is executed then eventually get notified about them.:
     Uncaught TypeError: Cannot read property 'replace' of null
      at t.call [as _next] (src/observers/BackgroundWorkStatusBarObserver.ts:17:74)
      at t.__tryOrUnsub (node_modules/rxjs/_esm5/internal/Subscriber.js:192:16)
      at t.next (node_modules/rxjs/_esm5/internal/Subscriber.js:130:22)
      at t._next (node_modules/rxjs/_esm5/internal/Subscriber.js:76:26)
      at t.next (node_modules/rxjs/_esm5/internal/Subscriber.js:53:18)
      at t.next (node_modules/rxjs/_esm5/internal/Subject.js:47:25)
      at t.EventStream.post (src/EventStream.ts:16:19)
      at EventEmitter.<anonymous> (src/omnisharp/server.ts:307:30)
      at k._fireEvent (src/omnisharp/server.ts:248:24)
      at k._handleEventPacket (src/omnisharp/server.ts:738:18)
      at k._onLineReceived (src/omnisharp/server.ts:703:22)
      at Interface._onLine (readline.js:337:10)
      at Interface._normalWrite (readline.js:482:12)
      at Socket.ondata (readline.js:194:10)
      at addChunk (internal/streams/readable.js:309:12)
      at readableAddChunk (internal/streams/readable.js:284:9)
      at Socket.Readable.push (internal/streams/readable.js:223:10)
      at Pipe.onStreamRead (internal/stream_base_commons.js:188:23)

  2) ReAnalyze: sln with several csproj's
       When re-analyze of all projects is executed then eventually get notified about them.:
     Error: done() called multiple times in test <ReAnalyze: sln with several csproj's When re-analyze of all projects is executed then eventually get notified about them.> of file /home/runner/work/omnisharp-vscode/omnisharp-vscode/out/test/integrationTests/reAnalyze.integration.test.js

[JoeRobich]

Additional flaky tests from #4849

Error: 2 tests failed.
  2 failing

  1) Code Action Rename sln filter with a csproj's
       "before all" hook for "Code actions can rename and open files":
     Uncaught TypeError: Cannot read property 'replace' of null
      at t.call [as _next] (src/observers/BackgroundWorkStatusBarObserver.ts:17:74)
      at t.__tryOrUnsub (node_modules/rxjs/_esm5/internal/Subscriber.js:192:16)
      at t.next (node_modules/rxjs/_esm5/internal/Subscriber.js:130:22)
      at t._next (node_modules/rxjs/_esm5/internal/Subscriber.js:76:26)
      at t.next (node_modules/rxjs/_esm5/internal/Subscriber.js:53:18)
      at t.next (node_modules/rxjs/_esm5/internal/Subject.js:47:25)
      at t.EventStream.post (src/EventStream.ts:16:19)
      at EventEmitter.<anonymous> (src/omnisharp/server.ts:307:30)
      at k._fireEvent (src/omnisharp/server.ts:248:24)
      at k._handleEventPacket (src/omnisharp/server.ts:738:18)
      at k._onLineReceived (src/omnisharp/server.ts:703:22)
      at Interface._onLine (readline.js:337:10)
      at Interface._normalWrite (readline.js:482:12)
      at Socket.ondata (readline.js:194:10)
      at addChunk (internal/streams/readable.js:309:12)
      at readableAddChunk (internal/streams/readable.js:284:9)
      at Socket.Readable.push (internal/streams/readable.js:223:10)
      at Pipe.onStreamRead (internal/stream_base_commons.js:188:23)

  2) Code Action Rename sln filter with a csproj's
       "before all" hook for "Code actions can rename and open files":
     Error: done() called multiple times in hook <Code Action Rename sln filter with a csproj's "before all" hook for "Code actions can rename and open files"> of file /home/runner/work/omnisharp-vscode/omnisharp-vscode/out/test/integrationTests/codeActionRename.integration.test.js
      at processTicksAndRejections (internal/process/task_queues.js:93:5)