Reenable invites

resources/qml/RoomList.qml

src/Cache.cpp

src/Cache.h

src/Cache_p.h

src/ChatPage.cpp

src/ChatPage.h

src/RoomList.cpp

src/RoomList.h

src/timeline/RoomlistModel.cpp

src/timeline/RoomlistModel.h

src/timeline/TimelineViewManager.cpp

src/timeline/TimelineViewManager.h

src/ui/Theme.cpp

src/ui/Theme.h