Clean Up qmake files

As openpass uses only cmake und qmake is now deprecated for openpass and not further developed, all the files regarding qmake could be deleted and cleaned up.

Possible Tasks:

1. Check if there are components, modules, tests or stuff which are not covered by cmake yet. If so, then refactor that in another ticket
2. Delete all .pro, .pri
3. Check if everything is still working

mentioned in merge request !15 (merged)

changed milestone to %Release v0.9

mentioned in commit bb016823

Issue can be closed with commit bb016823

closed