Tweaks discovered when using Compound overrides. (#4456)

- Fixes a bug where gradients wouldn't use the latest tokens after first use.
- Makes the bloom aware of colour overrides (and discovers a bug with dark mode).
- Decouples HomeScreenCell from the HomeScreenViewModel.Context (so it can be previewed with colour overrides).

ElementX/Sources/Screens/HomeScreen/View/HomeScreenRoomList.swift

@@ -24,7 +24,7 @@ struct HomeScreenRoomList: View {
         ForEach(context.viewState.visibleRooms) { room in
             switch room.type {
             case .placeholder:
-                HomeScreenRoomCell(room: room, context: context, isSelected: false)
+                HomeScreenRoomCell(room: room, isSelected: false, mediaProvider: context.mediaProvider, action: context.send)
                     .redacted(reason: .placeholder)
             case .invite:
                 HomeScreenInviteCell(room: room, context: context, hideInviteAvatars: context.viewState.hideInviteAvatars)
@@ -33,7 +33,7 @@ struct HomeScreenRoomList: View {
             case .room:
                 let isSelected = context.viewState.selectedRoomID == room.id
                 
-                HomeScreenRoomCell(room: room, context: context, isSelected: isSelected)
+                HomeScreenRoomCell(room: room, isSelected: isSelected, mediaProvider: context.mediaProvider, action: context.send)
                     .contextMenu {
                         if room.badges.isDotShown {
                             Button {