♿ [#2583] Make control of modal focusable in the right order

[jiromaykin]

issue: https://taiga.maykinmedia.nl/project/open-inwoner/us/2402

1. accessibility requirement "When a dialog closes, focus returns to the element that invoked the dialog"
2. making sure the Escape button doesn't interfere with closing of the navigation etc.
3. moving the KCM feedback button to bottom of footer for more logical Tab order

Effect:
after closing a modal your Tab focus should land on the button that opened it, meaning you can Tab backward or forward starting from the modal-opening-control button.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.13%. Comparing base (318aed7) to head (591d276).
Report is 36 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff              @@
##           develop    #1287       +/-   ##
============================================
+ Coverage    44.22%   95.13%   +50.90%     
============================================
  Files          972      983       +11     
  Lines        35571    35847      +276     
============================================
+ Hits         15733    34104    +18371     
+ Misses       19838     1743    -18095     

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