The CMakeManager uses createImportJob on reload which was previously
stopping on known folders. This lead to various issues, esp. when
switching branches we sometimes missed new contents in folders etc.

I don't remember anymore why this whole logic existed before,
potentially some not-so-smart performance optimization which breaks
things. Since I didn't add good comments back then, lets remove it
for now and see how it works. If things become slow we can always
optimize later on.

Generic manager test works, as does using it for real.