fix(Dropdown): fix handling of "Space" key

[layershifter]

Fixes #3146.
Fixes #3689.

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This PR moves the handling of Spacebar to Dropdown's scope instead of the global scope with EventListener. In any case these events should handled only when Dropdown is focused.

Another noticeable change is handling of Spacebar in openOnSpace(): now we will call preventDefault() only when e.target is non-editable element and needs to prevent default behavior to avoid scrolling.

[github-actions]

size-limit report

Path	Size
bundle-size/dist/Button.size.js	66.39 KB (0%)
bundle-size/dist/Icon.size.js	30.58 KB (0%)
bundle-size/dist/Image.size.js	61.63 KB (0%)
bundle-size/dist/Modal.size.js	76.65 KB (0%)
bundle-size/dist/Portal.size.js	47.78 KB (0%)

[codecov-commenter]

Codecov Report

Merging #4041 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #4041   +/-   ##
=======================================
  Coverage   99.84%   99.84%           
=======================================
  Files         183      183           
  Lines        3276     3280    +4     
=======================================
+ Hits         3271     3275    +4     
  Misses          5        5           

Impacted Files	Coverage Δ
src/modules/Dropdown/Dropdown.js	100.00% <100.00%> (ø)

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