Linux: Fix remaining file/folder picker issues (#24)

I fixed the remaining Linux file picker issues after testing on Steam Deck. User profile images, mod manager, title manager, and DLC directory were still using the old file picker methods and not the helper methods. I could only apply the helper method to user profiles, but I came up with a workaround for the others.

The reason for the draft PR: I'd ideally like to fix the other three at the helper level, so maybe @greem can help with that since since he wrote the initial implementation.

Reviewed-on: https://git.ryujinx.app/projects/Ryubing/pulls/24

src/Ryujinx/UI/ViewModels/TitleUpdateViewModel.cs

@@ -11,6 +11,7 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
+using static Ryujinx.Ava.Utilities.StorageProviderExtensions;
 
 namespace Ryujinx.Ava.UI.ViewModels
 {
@@ -148,7 +149,7 @@ namespace Ryujinx.Ava.UI.ViewModels
 
         public async Task Add()
         {
-            IReadOnlyList<IStorageFile> result = await _storageProvider.OpenFilePickerAsync(new FilePickerOpenOptions
+            IReadOnlyList<IStorageFile> result = await CoreDumpable(() => _storageProvider.OpenFilePickerAsync(new FilePickerOpenOptions
             {
                 AllowMultiple = true,
                 FileTypeFilter = new List<FilePickerFileType>
@@ -160,7 +161,7 @@ namespace Ryujinx.Ava.UI.ViewModels
                         MimeTypes = ["application/x-nx-nsp"],
                     },
                 },
-            });
+            }));
 
             int totalUpdatesAdded = 0;
             foreach (IStorageFile file in result)