protocol GUI refresh issues

[DStrelak]

Describe the bug
While changing the size of the protocols, the scroll bars behave like if there are several refresh events.
Also, if you e.g. change view to Advanced, some elements might not be shown (they are not rendered at all)

To Reproduce
Steps to reproduce the behavior:

1. add xmipp3 - correlation alignment protocol
2. open edit window
3. which to Advanced mode
4. horizontal scrollbar appears (even though it's useless), and vertical has typically wrong slider.
5. try to resize the window. The thumb tends to show/ignore the 'page down/up space' in the scrollbar.

Expected behavior
Only necessary sliders should appear. All GUI elements should be properly rendered after GUI refresh (changing some toggle)

Screenshots
Notice that some text is rendered at the very bottom of the window, but the scrollbar looks like there's nowhere else to go.

Desktop (please complete the following information):

• OS: Ubuntu 18
• Version: devel as of today