Ensure proper disposal of accounts

Author: d2dyno1

src/Sdk/SecureFolderFS.Sdk/ViewModels/Views/Wizard/DataSources/AccountSourceWizardViewModel.cs

@@ -188,6 +188,8 @@ private async Task SelectAccountAsync(AccountViewModel? accountViewModel, Cancel
         public override void Dispose()
         {
             NavigationRequested = null;
+            Accounts.Select(x => x != SelectedAccount).DisposeAll();
+            Accounts.Clear();
         }
     }
 }

src/Sdk/SecureFolderFS.Sdk/ViewModels/Views/Wizard/SourceSelectionWizardViewModel.cs

@@ -58,9 +58,6 @@ public Task<IResult> TryCancelAsync(CancellationToken cancellationToken)
         /// <inheritdoc/>
         public override async void OnAppearing()
         {
-            if (!Sources.IsEmpty())
-                return;
-
             var sources = await VaultFileSystemService.GetSourcesAsync(_vaultCollectionModel, _mode).ToArrayAsyncImpl();
             Sources.DisposeAll();
             Sources.Clear();