custom collection playback order (#64)

* add custom index to collection items

* add custom collection order to ui

* cleanup

ErsatzTV.Core.Tests/Fakes/FakeMediaCollectionRepository.cs

@@ -14,17 +14,22 @@ namespace ErsatzTV.Core.Tests.Fakes
         private readonly Map<int, List<MediaItem>> _data;
 
         public FakeMediaCollectionRepository(Map<int, List<MediaItem>> data) => _data = data;
+
         public Task<Collection> Add(Collection collection) => throw new NotSupportedException();
         public Task<bool> AddMediaItem(int collectionId, int mediaItemId) => throw new NotSupportedException();
         public Task<bool> AddMediaItems(int collectionId, List<int> mediaItemIds) => throw new NotSupportedException();
-
         public Task<Option<Collection>> Get(int id) => throw new NotSupportedException();
         public Task<Option<Collection>> GetCollectionWithItems(int id) => throw new NotSupportedException();
         public Task<Option<Collection>> GetCollectionWithItemsUntracked(int id) => throw new NotSupportedException();
+
+        public Task<Option<Collection>> GetCollectionWithCollectionItemsUntracked(int id) =>
+            throw new NotSupportedException();
+
         public Task<List<Collection>> GetAll() => throw new NotSupportedException();
         public Task<Option<List<MediaItem>>> GetItems(int id) => Some(_data[id].ToList()).AsTask();
         Task<bool> IMediaCollectionRepository.Update(Collection collection) => throw new NotSupportedException();
         public Task Delete(int collectionId) => throw new NotSupportedException();
         public Task<List<int>> PlayoutIdsUsingCollection(int collectionId) => throw new NotSupportedException();
+        public Task<bool> IsCustomPlaybackOrder(int collectionId) => false.AsTask();
     }
 }