Implement month separator for the Gallery.

Improve day separator rendering in the timeline.
Use Today, Yesterday, and the name of the day if less than 7 days and do not render the year for the current year.
Improve date format for the media viewer.
Rework how date and time are computed.
ActionListView: Time can take more space, so update the layout.

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/RustMatrixRoom.kt

@@ -235,7 +235,7 @@ class RustMatrixRoom(
                     RoomMessageEventMessageType.VIDEO,
                     RoomMessageEventMessageType.AUDIO,
                 ),
-                dateDividerMode = DateDividerMode.DAILY,
+                dateDividerMode = DateDividerMode.MONTHLY,
             ).let { inner ->
                 createTimeline(inner, mode = Timeline.Mode.MEDIA)
             }