Fix roomlist positioning when changing rooms

The room list is supposed to center the new room, but, since the current room as stored in SortFilterRoomTreeModel is only updated after we're jumping to the room, mostly just jumped to the old room.

src/rooms/RoomListPage.qml

@@ -96,7 +96,10 @@ Kirigami.Page {
         function onCurrentSpaceChanged() {
             treeView.expandRecursively();
         }
+    }
 
+    Connections {
+        target: RoomManager.sortFilterRoomTreeModel
         function onCurrentRoomChanged() {
             treeView.positionViewAtIndex(RoomManager.sortFilterRoomTreeModel.currentRoomIndex(), TableView.AlignVCenter)
         }

src/rooms/models/sortfilterroomtreemodel.cpp

@@ -134,6 +134,7 @@ void SortFilterRoomTreeModel::setActiveSpaceId(const QString &spaceId)
 void SortFilterRoomTreeModel::setCurrentRoom(NeoChatRoom *room)
 {
     m_currentRoom = room;
+    Q_EMIT currentRoomChanged();
 }
 
 SortFilterRoomTreeModel::Mode SortFilterRoomTreeModel::mode() const

src/rooms/models/sortfilterroomtreemodel.h

@@ -104,6 +104,7 @@ Q_SIGNALS:
     void filterTextChanged();
     void activeSpaceIdChanged();
     void modeChanged();
+    void currentRoomChanged();
 
 private:
     Mode m_mode = All;