Add another option to mark a test as manual and use this for some
existing.
Manual tests will not be added as a ctest, but they can still get
executed explicitly.
Beside this allow to use a condition when using add_qtc_test().
Change-Id: I03d5397db36c0a2c9ee506a4214ed68fae6ad6e7
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
