Optimize includes a bit

CMakeLists.txt

src/ChatPage.cpp

src/CommunitiesList.cpp

src/CommunitiesList.h

src/CommunitiesListItem.cpp

src/CommunitiesListItem.h

src/LoginPage.cpp

src/MainWindow.cpp

src/RegisterPage.cpp

src/RoomInfoListItem.cpp

src/RoomList.cpp

src/SideBarActions.cpp

src/SideBarActions.h

src/Splitter.cpp

src/Splitter.h

src/TextInputWidget.cpp

src/TextInputWidget.h

src/TopRoomBar.cpp

src/TopRoomBar.h

src/TrayIcon.cpp