Move remaining code to app module

There's still some stuff that could potentially go elsewhere but I think it's enough for now.

src/libneochat/CMakeLists.txt

@@ -30,6 +30,7 @@ target_sources(LibNeoChat PRIVATE
     enums/roomsortorder.h
     events/imagepackevent.cpp
     events/pollevent.cpp
+    jobs/neochatgetcommonroomsjob.cpp
     models/actionsmodel.cpp
     models/completionmodel.cpp
     models/completionproxymodel.cpp