Cleanup extracted files (#13760)

* Cleanup extracted files

* Pagination and fixes

* Add migration for attachments to MigrateLibraryDb

* Unify attachment handling

* Don't extract again if files were already extracted

* Fix MKS attachment extraction

* Always run full extraction on mks

* Don't try to extract mjpeg streams as attachments

* Fallback to check if attachments were extracted to cache folder

* Fixup

src/Jellyfin.Database/Jellyfin.Database.Implementations/Entities/AttachmentStreamInfo.cs

@@ -25,7 +25,7 @@ public class AttachmentStreamInfo
     /// <summary>
     /// Gets or Sets the codec of the attachment.
     /// </summary>
-    public required string Codec { get; set; }
+    public string? Codec { get; set; }
 
     /// <summary>
     /// Gets or Sets the codec tag of the attachment.