Voice message: variable play back speed (#5121)

* Implement voice message variable playback speed

* Move playback speed string to Untranslated

https://github.com/element-hq/element-x-ios/pull/5121#discussion_r2822631371

* Address review feedback for voice message playback speed

- Persist voice message playback speed as an enum in AppSettings instead of storing an index.
- Update playback speed cycling to derive from enum allCases and safely fall back to `.default` if the stored value cannot be resolved.
- Apply runtime speed updates in AudioPlayer only when the player is in the `.playing` state.
- Keep MediaPlayerProviderTests formatting/indentation style intact while retaining mock playback speed setup.
- Regenerate preview snapshots for:
  - PlaybackSpeedButton
  - VoiceMessageRoomPlaybackView
  - VoiceMessageRoomTimelineView

* Move VoiceMessagePlaybackSpeed outside AppSettings, remove speedRatio

* Stabilize PlaybackSpeedButton width

* Sync voice-message speed label

- Add voiceMessagePlaybackSpeed to TimelineViewState and bind it from appSettings.$voiceMessagePlaybackSpeed.
- Pass that timeline-level speed into VoiceMessageRoomPlaybackView and use it for PlaybackSpeedButton, so labels update consistently across items.
- Use @EnvironmentObject in VoiceMessageRoomTimelineContent so the view re-renders when timeline context state changes.
- In WaveformInteractionModifier, add .allowsHitTesting(showCursor) to the cursor interaction view so hidden pre-playback cursor hit area does not steal taps from the speed button.

ElementX/Sources/Services/Audio/Player/AudioPlayer.swift

@@ -48,7 +48,8 @@ class AudioPlayer: NSObject, AudioPlayerProtocol {
     private let releaseAudioSessionTimeoutInterval = 5.0
     
     private(set) var playbackURL: URL?
-    
+    private(set) var playbackSpeed: Float = 1.0
+
     private var deinitInProgress = false
     
     var duration: TimeInterval {
@@ -106,7 +107,7 @@ class AudioPlayer: NSObject, AudioPlayerProtocol {
     func play() {
         isStopped = false
         setupAudioSession()
-        internalAudioPlayer?.play()
+        internalAudioPlayer?.rate = playbackSpeed
     }
     
     func pause() {
@@ -128,7 +129,14 @@ class AudioPlayer: NSObject, AudioPlayerProtocol {
         let time = progress * duration
         await internalAudioPlayer.seek(to: CMTime(seconds: time, preferredTimescale: 60))
     }
-    
+
+    func setPlaybackSpeed(_ speed: Float) {
+        playbackSpeed = speed
+        if state == .playing {
+            internalAudioPlayer?.rate = speed
+        }
+    }
+
     // MARK: - Private
     
     private func setupAudioSession() {