Set invited and left rooms position in model

Invited rooms at the start, left rooms at the end, with the bonus effect
of fixing the roomList height problem.

harmonyqml/components/sidePane/RoomList.qml

@@ -8,9 +8,9 @@ ListView {
 
     property int childrenHeight: 36
     property int sectionHeight: 16 + spacing
-    property int contentHeight: 0
+    property int contentHeight: getContentHeight()
 
-    onCountChanged: {
+    function getContentHeight() {
         var sections = []
 
         for (var i = 0; i < model.count; i++) {
@@ -24,6 +24,11 @@ ListView {
             sectionHeight * sections.length
     }
 
+    Connections {
+        target: model
+        onChanged: getContentHeight()
+    }
+
     id: roomList
     spacing: 8
     model: Backend.models.rooms.get(forUserId)