Add OriginalLanguage as option to PreferredAudioLanguage (#12579)

* Add OriginalLanguage as option to PreferredAudioLanguage

* Support for multiple original languages

* Add original audio stream indicator

* Fetch OriginalLanguage from TMDB

* Adapt to EFCore refactor

* Fix PlayDefaultAudioTrack OriginalLanguage behavior

* Fix better PlayDefaultAudioTrack OriginalLanguage behavior

* Add comment to ItemFields

* Improved PlayDefaultAudioTrack behavior

* Add migration for original language

* Use sting.Equals for string comparisons

* Always set dto OriginalLanguage

* Remove OriginalLanguage from ItemFields

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Co-authored-by: Lampan-git <lampan-git@users.noreply.github.com>

src/Jellyfin.Database/Jellyfin.Database.Implementations/Entities/Libraries/ItemMetadata.cs

@@ -62,6 +62,16 @@ namespace Jellyfin.Database.Implementations.Entities.Libraries
         [StringLength(1024)]
         public string? OriginalTitle { get; set; }
 
+        /// <summary>
+        /// Gets or sets the original language.
+        /// </summary>
+        /// <remarks>
+        /// Max length = 1024.
+        /// </remarks>
+        [MaxLength(1024)]
+        [StringLength(1024)]
+        public string? OriginalLanguage { get; set; }
+
         /// <summary>
         /// Gets or sets the sort title.
         /// </summary>