Add Forward action to MediaDetailsBottomSheet. Closes #5454

Improve API of Callback when forwarding Event.

libraries/mediaviewer/api/src/main/kotlin/io/element/android/libraries/mediaviewer/api/MediaGalleryEntryPoint.kt

@@ -24,5 +24,6 @@ interface MediaGalleryEntryPoint : FeatureEntryPoint {
     interface Callback : Plugin {
         fun onBackClick()
         fun onViewInTimeline(eventId: EventId)
+        fun forwardEvent(eventId: EventId)
     }
 }

libraries/mediaviewer/api/src/main/kotlin/io/element/android/libraries/mediaviewer/api/MediaViewerEntryPoint.kt

@@ -31,6 +31,7 @@ interface MediaViewerEntryPoint : FeatureEntryPoint {
     interface Callback : Plugin {
         fun onDone()
         fun onViewInTimeline(eventId: EventId)
+        fun onForwardEvent(eventId: EventId)
     }
 
     data class Params(