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/AudioPlayerState.swift

@@ -36,6 +36,7 @@ class AudioPlayerState: ObservableObject, Identifiable {
     /// It's similar to `playbackState`, with the a difference: `.loading`
     /// updates are delayed by a fixed amount of time
     @Published private(set) var playerButtonPlaybackState: AudioPlayerPlaybackState
+    @Published private(set) var playbackSpeed: Float = 1.0
 
     private weak var audioPlayer: AudioPlayerProtocol?
     private var audioPlayerSubscription: AnyCancellable?
@@ -110,7 +111,12 @@ class AudioPlayerState: ObservableObject, Identifiable {
     func reportError() {
         playbackState = .error
     }
-    
+
+    func setPlaybackSpeed(_ speed: Float) {
+        playbackSpeed = speed
+        audioPlayer?.setPlaybackSpeed(speed)
+    }
+
     // MARK: - Private
     
     private func subscribeToAudioPlayer(audioPlayer: AudioPlayerProtocol) {