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/Mocks/Generated/GeneratedMocks.swift

@@ -1222,6 +1222,11 @@ class AudioPlayerMock: AudioPlayerProtocol, @unchecked Sendable {
         set(value) { underlyingState = value }
     }
     var underlyingState: MediaPlayerState!
+    var playbackSpeed: Float {
+        get { return underlyingPlaybackSpeed }
+        set(value) { underlyingPlaybackSpeed = value }
+    }
+    var underlyingPlaybackSpeed: Float!
     var actions: AnyPublisher<AudioPlayerAction, Never> {
         get { return underlyingActions }
         set(value) { underlyingActions = value }
@@ -1450,6 +1455,47 @@ class AudioPlayerMock: AudioPlayerProtocol, @unchecked Sendable {
         }
         await seekToClosure?(progress)
     }
+    //MARK: - setPlaybackSpeed
+
+    var setPlaybackSpeedUnderlyingCallsCount = 0
+    var setPlaybackSpeedCallsCount: Int {
+        get {
+            if Thread.isMainThread {
+                return setPlaybackSpeedUnderlyingCallsCount
+            } else {
+                var returnValue: Int? = nil
+                DispatchQueue.main.sync {
+                    returnValue = setPlaybackSpeedUnderlyingCallsCount
+                }
+
+                return returnValue!
+            }
+        }
+        set {
+            if Thread.isMainThread {
+                setPlaybackSpeedUnderlyingCallsCount = newValue
+            } else {
+                DispatchQueue.main.sync {
+                    setPlaybackSpeedUnderlyingCallsCount = newValue
+                }
+            }
+        }
+    }
+    var setPlaybackSpeedCalled: Bool {
+        return setPlaybackSpeedCallsCount > 0
+    }
+    var setPlaybackSpeedReceivedSpeed: Float?
+    var setPlaybackSpeedReceivedInvocations: [Float] = []
+    var setPlaybackSpeedClosure: ((Float) -> Void)?
+
+    func setPlaybackSpeed(_ speed: Float) {
+        setPlaybackSpeedCallsCount += 1
+        setPlaybackSpeedReceivedSpeed = speed
+        DispatchQueue.main.async {
+            self.setPlaybackSpeedReceivedInvocations.append(speed)
+        }
+        setPlaybackSpeedClosure?(speed)
+    }
 }
 class AudioRecorderMock: AudioRecorderProtocol, @unchecked Sendable {
     var actions: AnyPublisher<AudioRecorderAction, Never> {