Add iOS AVPlayer voice backend

apps/ios/TeleTuiIOS/Sources/TeleTuiIOSCore/PlatformServices.swift

@@ -166,6 +166,28 @@ public protocol VoicePlayback: Sendable {
     func seek(to seconds: TimeInterval) async
 }
 
+public actor SystemVoicePlayer: VoicePlayback {
+    private var player: AVPlayer?
+
+    public init() {}
+
+    public func load(url: URL) async throws {
+        player = AVPlayer(url: url)
+    }
+
+    public func play() async {
+        player?.play()
+    }
+
+    public func pause() async {
+        player?.pause()
+    }
+
+    public func seek(to seconds: TimeInterval) async {
+        await player?.seek(to: CMTime(seconds: seconds, preferredTimescale: 600))
+    }
+}
+
 public actor RecordingVoicePlayer: VoicePlayback {
     public private(set) var loadedURL: URL?
     public private(set) var isPlaying = false