Add more playback rates for MPV

Model/Player/Backends/MPVBackend.swift

@@ -92,6 +92,14 @@ final class MPVBackend: PlayerBackend {
     internal var controlsUpdates = false
     private var timeObserverThrottle = Throttle(interval: 2)
 
+    var suggestedPlaybackRates: [Double] {
+        [0.1, 0.25, 0.3, 0.33, 0.5, 0.67, 0.8, 1, 1.25, 1.5, 1.75, 2, 3, 4]
+    }
+
+    func canPlayAtRate(_ rate: Double) -> Bool {
+        rate > 0 && rate <= 100
+    }
+
     var tracks: Int {
         client?.tracksCount ?? -1
     }