Loading and End of Timeline Delegates

Add delegate for showing the user a loading indicator and for the beginning of the timeline.

BUG: 455045
BUG: 465285

src/qml/EventDelegate.qml

@@ -99,6 +99,7 @@ DelegateChooser {
             connection: root.connection
         }
     }
+
     DelegateChoice {
         roleValue: DelegateType.LiveLocation
         delegate: LiveLocationDelegate {
@@ -107,6 +108,18 @@ DelegateChooser {
         }
     }
 
+    DelegateChoice {
+        roleValue: DelegateType.Loading
+        delegate: LoadingDelegate {}
+    }
+
+    DelegateChoice {
+        roleValue: DelegateType.TimelineEnd
+        delegate: TimelineEndDelegate {
+            room: root.room
+        }
+    }
+
     DelegateChoice {
         roleValue: DelegateType.Other
         delegate: Item {}