Improve the usability of HFIR powder reduction GUI

[Wenduo Zhou]

There are a few usability issues with HFIR powder reduction GUI. Here is the list:

1. Tooltips: they just show up as black rectangles;
2. If there is any error, there is a segmentation fault on exit;
3. Need a separate window for logging;
4. It is not finalized to apply processed vanadium spectrum;
5. Enable and disable buttons automatically to guide user to maintain on the right path

[Stuart Campbell]

This ticket has been transferred to github issue ​12532