qt,tests: Move remarks test out and extend it

* lang/qt/tests/t-various.cpp (testRemarks): Move out.
* lang/qt/tests/t-remarks.cpp: New.
* lang/qt/tests/Makefile.am: Update accordingly.

While t-various is nice to add a quick test for more
extensive stuff it is better to move it in its own test.

This also tests with a key that has only a single uid.