fix: resolve 5 SonarQube S2589 issues and improve null handling

src/ConnectedMode/Migration/RoslynProjectProvider.cs

@@ -58,7 +58,7 @@ public IReadOnlyList<Project> Get()
                 return new List<Project>();
             }
 
-            return wrappedWorkspace?.CurrentSolution?.Projects.ToList();
+            return wrappedWorkspace.CurrentSolution.Projects.ToList();
         }
     }
 }

src/ConnectedMode/Persistence/SolutionBindingRepository.cs

@@ -47,7 +47,7 @@ BoundSonarQubeProject ILegacySolutionBindingRepository.Read(string configFilePat
         return bindingJsonModel switch
         {
             null => null,
-            not null => bindingJsonModelConverter.ConvertFromModelToLegacy(bindingJsonModel, credentialsLoader.Load(bindingJsonModel.ServerUri))
+            _ => bindingJsonModelConverter.ConvertFromModelToLegacy(bindingJsonModel, credentialsLoader.Load(bindingJsonModel.ServerUri))
         };
     }
 

src/Core/FileMonitor/SingleFileMonitor.cs

@@ -135,7 +135,6 @@ private void CleanUpEmptyDirectory()
 
         private void OnFileChanged(object sender, FileSystemEventArgs args)
         {
-            Debug.Assert(fileChangedHandlers != null, "Not expecting file system events to be monitored if there are no listeners");
             if (fileChangedHandlers == null || disposedValue)
             {
                 return;

src/Integration/Helpers/OutputWindowService.cs

@@ -45,7 +45,6 @@ public OutputWindowService([Import(typeof(SVsServiceProvider))] IServiceProvider
         public void Show()
         {
             var sonarLintOutputPane = VsShellUtils.GetOrCreateSonarLintOutputPane(serviceProvider);
-            Debug.Assert(sonarLintOutputPane != null, "Failed to create SonarLint pane");
 
             if (sonarLintOutputPane == null)
             {

src/IssueViz/IssueVisualizationControl/ViewModels/Commands/NavigateToRuleDescriptionCommand.cs

@@ -83,7 +83,7 @@ public object[] ConvertBack(
             CultureInfo culture)
         {
             Debug.Fail("We should not hit here");
-            return null;
+            return Array.Empty<object>();
         }
     }
 }