Test fixups w.r.t WinForms type removal

See: dotnet/wpf#2169

We need to react to this change in our test repo and remove the type references in the following tests:

Feature | Test Case | Reproduced OS | Main Log | Detail Log
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ElementServices | /Name="Var(MouseButtonApp_WpfApplication_WindowsFormSource)" /SubArea="Input" | All test OSes | Log: ********* Starting Test: Var(MouseButtonApp_WpfApplication_WindowsFormSource) ********* Repro Arguments: /Name=Var(MouseButtonApp_WpfApplication_WindowsFormSource) /Are a=ElementServices /SubArea=Input ********* Begin Variation: InputApp ********* … … Creating 'WindowsFormSource' surface... Creating a WindowsFormSource object Unhandled exception occurred in dispatcher. System.MissingMethodException: Method not found: 'Void System.Windows.Forms.Cont rol.add_ContextMenuChanged(System.EventHandler)'.    at System.Windows.Forms.Integration.ElementHost.StartPropertyMapping()    at System.Windows.Forms.Integration.ElementHost..ctor() in G:\wpf_private\src \Microsoft.DotNet.Wpf\src\WindowsFormsIntegration\System\Windows\Integration\Ele mentHost.cs:line 85    at Microsoft.Test.WindowsForms.WindowsFormSource.InitializeComponent() in /_/ src/Test/Common/Code/Microsoft/Test/WindowsForms/WindowsFormsSource.cs:line 152    at Microsoft.Test.WindowsForms.WindowsFormSource..ctor() in /_/src/Test/Commo n/Code/Microsoft/Test/WindowsForms/WindowsFormsSource.cs:line 59 … … | Var(MouseButtonApp_WpfApplication_WindowsFormSource)_3.1
ElementServices | /Name="Var(Border_Border_Canvas_AllFocusable_HandledEventsToo-WpfApplication-WindowsFormSource)" /SubArea="InputSequence" | All test OSes | Log: ********* Starting Test: Var(Border_Border_Canvas_AllFocusable_HandledEventsToo- WpfApplication-WindowsFormSource) ********* Repro Arguments: /Name=Var(Border_Border_Canvas_AllFocusable_HandledEventsToo-Wp fApplication-WindowsFormSource) /Area=ElementServices /SubArea=InputSequence ********* Begin Variation: InputSequenceApp ********* … … QualityVault: Process: 3916 now marked for tracking. Variation loop beginning... In CreateTestContainer... In ActionSequenceTestEngine.RunTestAction... 'TestContainer' is in storage. Creating 'WindowsFormSource' surface... Creating a WindowsFormSource object Unhandled exception occurred in dispatcher. System.MissingMethodException: Method not found: 'Void System.Windows.Forms.Cont rol.add_ContextMenuChanged(System.EventHandler)'.    at System.Windows.Forms.Integration.ElementHost.StartPropertyMapping()    at System.Windows.Forms.Integration.ElementHost..ctor() in G:\wpf_private\src \Microsoft.DotNet.Wpf\src\WindowsFormsIntegration\System\Windows\Integration\Ele mentHost.cs:line 85    at Microsoft.Test.WindowsForms.WindowsFormSource.InitializeComponent() in /_/ src/Test/Common/Code/Microsoft/Test/WindowsForms/WindowsFormsSource.cs:line 152    at Microsoft.Test.WindowsForms.WindowsFormSource..ctor() in /_/src/Test/Commo n/Code/Microsoft/Test/WindowsForms/WindowsFormsSource.cs:line 59    at Avalon.Test.CoreUI.Trusted.SurfaceFramework.Initialize(String typeOfSurfac e, Int32 left, Int32 top, Int32 width, Int32 height, Boolean visibleSurface)    at Avalon.Test.CoreUI.Trusted.SurfaceFramework..ctor(String typeOfSurface, In t32 left, Int32 top, Int32 width, Int32 height)    at Avalon.Test.CoreUI.Common.StubTestContainer.DisplayObject(Object visual, I nt32 x, Int32 y, Int32 w, Int32 h) … … | Var(Border_Border_Canvas_AllFocusable_HandledEventsToo-WpfApplication-WindowsFormSource)_3.1

WindowsFormsIntegration | DrtWindowsFormsIntegration () | All test OSes | Log: ********* Starting Test: DrtWindowsFormsIntegration() ********* Repro Arguments: /Name=DrtWindowsFormsIntegration() /Area=WindowsFormsIntegration Clearing click once cache. ********* Begin Variation: DrtWindowsFormsIntegration() ********* QualityVault: Process: 2008 now marked for tracking. DrtWindowsFormsIntegration (owner: ) >Suite (owner:         ): WindowsFormsHostTestSuite >Suite (owner:         ): ElementHostTestSuite   Non-zero exit code: 1 *************************************** Variation Result: Fail *************************************** ********* End Variation  : DrtWindowsFormsIntegration() ********* Repro Arguments: /Name=DrtWindowsFormsIntegration() /Area=WindowsFormsIntegration /SubArea= ********* Ending Test: DrtWindowsFormsIntegration() ********* | DrtWindowsFormsIntegration()
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