[DDA Port] Fix various issues with window redraw and event handling

[olanti-p]

Summary

SUMMARY: Bugfixes "[DDA Port] Fix various issues with window redraw and event handling"

Purpose of change

Fix window getting unresponsive on long operations.
Fix #2015

Describe the solution

Stuff being ported:

• Documentation improvements from:
  • Fix inventory UI highlight not displayed when opening the UI or resizing the window CleverRaven/Cataclysm-DDA#44633
  • Add some documentation for ui_manager CleverRaven/Cataclysm-DDA#56281
• Handle system events during long operations:
  • Handle window events during long operations CleverRaven/Cataclysm-DDA#50360
• Fix artifacts in the undrawn part of the window:
  • Fix rendering routine on native wayland CleverRaven/Cataclysm-DDA#51053
  • Fix glitched graphics in undrawn area of the window CleverRaven/Cataclysm-DDA#56215

Describe alternatives you've considered

That single clear call should've been enough, but I've decided to go an extra mile and port fixes for related issues.

Testing

Can no longer repro the bug with the repro steps described in linked issue.

[Coolthulhu]

Wow, the implementation is ugly. bool params (with default values), direct calls to global input manager from unrelated classes, functions with over 3 bool params...

I guess it's OK for now, but it's a big // TODO: Refactor.