Basic download implementation

ios/JellyfinAudioPlayer/AppDelegate.m

@@ -11,6 +11,7 @@
 #import <FlipperKitNetworkPlugin/FlipperKitNetworkPlugin.h>
 #import <SKIOSNetworkPlugin/SKIOSNetworkAdapter.h>
 #import <FlipperKitReactPlugin/FlipperKitReactPlugin.h>
+#import <RNFSManager.h>
 
 static void InitializeFlipper(UIApplication *application) {
   FlipperClient *client = [FlipperClient sharedClient];
@@ -59,4 +60,9 @@ static void InitializeFlipper(UIApplication *application) {
 #endif
 }
 
+- (void)application:(UIApplication *)application handleEventsForBackgroundURLSession:(NSString *)identifier completionHandler:(void (^)())completionHandler
+{
+  [RNFSManager setCompletionHandlerForIdentifier:identifier completionHandler:completionHandler];
+}
+
 @end