macosx: Implement representedItemsAtIndexPaths for shows data source

Signed-off-by: Claudio Cambra <developer@claudiocambra.com>

modules/gui/macosx/library/video-library/VLCLibraryShowsDataSource.m

@@ -149,6 +149,24 @@
     return show.episodes[indexPath.item];
 }
 
+- (NSArray<VLCLibraryRepresentedItem *> *)representedItemsAtIndexPaths:(NSSet<NSIndexPath *> *const)indexPaths
+                                                     forCollectionView:(NSCollectionView *)collectionView
+{
+    NSMutableArray<VLCLibraryRepresentedItem *> * const representedItems =
+        [NSMutableArray arrayWithCapacity:indexPaths.count];
+
+    for (NSIndexPath * const indexPath in indexPaths) {
+        const id<VLCMediaLibraryItemProtocol> libraryItem =
+            [self libraryItemAtIndexPath:indexPath forCollectionView:collectionView];
+        VLCLibraryRepresentedItem * const representedItem =
+            [[VLCLibraryRepresentedItem alloc] initWithItem:libraryItem
+                                                 parentType:self.currentParentType];
+        [representedItems addObject:representedItem];
+    }
+
+    return representedItems;
+}
+
 - (NSInteger)numberOfSectionsInCollectionView:(NSCollectionView *)collectionView
 {
     return self.showsArray.count;