Get SVsSolution service instead of IVsSolution (#36226)

* Get SVsSolution service instead of IVsSolution

* Use the correct GetService overload

Author: tmat

src/VisualStudio/Core/Def/Implementation/ProjectSystem/VisualStudioWorkspaceImpl.cs

@@ -106,7 +106,7 @@ public VisualStudioWorkspaceImpl(ExportProvider exportProvider, IAsyncServicePro
             _projectionBufferFactoryService = exportProvider.GetExportedValue<IProjectionBufferFactoryService>();
             _projectCodeModelFactory = exportProvider.GetExport<IProjectCodeModelFactory>();
 
-            _lazyVsSolution = new Lazy<IVsSolution>(() => exportProvider.GetExport<SVsServiceProvider>().Value.GetService<IVsSolution>());
+            _lazyVsSolution = new Lazy<IVsSolution>(() => exportProvider.GetExport<SVsServiceProvider>().Value.GetService<IVsSolution, SVsSolution>());
 
             // We fetch this lazily because VisualStudioProjectFactory depends on VisualStudioWorkspaceImpl -- we have a circularity. Since this
             // exists right now as a compat shim, we'll just do this.

src/VisualStudio/TestUtilities2/ProjectSystemShim/Framework/TestEnvironment.vb

@@ -158,7 +158,7 @@ Namespace Microsoft.VisualStudio.LanguageServices.UnitTests.ProjectSystemShim.Fr
 
             Public Function GetService(serviceType As Type) As Object Implements System.IServiceProvider.GetService
                 Select Case serviceType
-                    Case GetType(IVsSolution), GetType(SVsSolution)
+                    Case GetType(SVsSolution)
                         Return VsSolutionMock
 
                     Case GetType(SComponentModel)