Fold experiments

[mmalczak]

I have refactored the code for ease of development.
I have added independent layouts, one with widgets that cannot be folded and another one with widgets to fold.

[marmeladapk]

• Add maximum height for submit and terminate buttons
  
• Minimum width is too low when scheduler settings are hidden -
  
  
  • maybe make a single large row for recompute and load buttons
  • maybe base minimum width on parameters - this might be tricky if there are groups
• expand window to new minimum width when expanding scheduler settings (now it's expanded when moving/resizing)
  
• remember state of managment expansion
• add text next to the expansion button "expand/hide scheduler settings"

[marmeladapk]

Buttons are resized, but still the whole panel housing them scales.

Expanding and collapsing options changes the window size even if it's larger than minimum.

Minimum width seems to be the same as on upstream now regardless if settings are expanded or collapsed. I wanted to be able to make the window narrower with collapsed options.

Change text "Options" to "Scheduler settings" (it's called that elsewhere in the GUI).

[mmalczak]

Implemented