Improve interrupt handling and send signal to current loop

[fepitre]

Closes QubesOS/qubes-issues#9410

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 11 lines in your changes missing coverage. Please review.

Project coverage is 77.17%. Comparing base (234bd95) to head (d7c3ee9).
Report is 12 commits behind head on main.

Files with missing lines	Patch %	Lines
qubesbuilder/cli/cli_base.py	47.61%	11 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #149      +/-   ##
==========================================
- Coverage   78.72%   77.17%   -1.56%     
==========================================
  Files          47       47              
  Lines        5353     5366      +13     
==========================================
- Hits         4214     4141      -73     
- Misses       1139     1225      +86     

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[fepitre]

@marmarek can you merge it not too late, I've several rogue dispvms on runner...