Sliding sync tweaks (#470)

* Show the splash screen again after failing to restore a session

* Fix visible rooms cold cache not working. Construct the visibleRoomsView before calling the sliding sync builder, process invalid entries directly if the allRoomsView is not available

* Stop building custom identifiers for invalidated rooms, we still have duplicates coming from filled ones.

* Fix visibleItemRangePublisher debouncer, guard against changing the range while the view isn't "live" yet

* Add more logs

ElementX/Sources/Screens/HomeScreen/HomeScreenModels.swift

@@ -42,9 +42,18 @@ enum HomeScreenViewAction {
     case updatedVisibleItemRange(Range<Int>)
 }
 
-enum HomeScreenRoomListMode {
+enum HomeScreenRoomListMode: CustomStringConvertible {
     case skeletons
     case rooms
+    
+    var description: String {
+        switch self {
+        case .rooms:
+            return "Showing rooms"
+        case .skeletons:
+            return "Showing placeholders"
+        }
+    }
 }
 
 struct HomeScreenViewState: BindableState {