fix: hide onboarding banner and popup after onboarding is completed

[aerodeval]

the Help Center banner is always visible in the menu even after user is familiar with the product which is sometimes annoying

this pr aims to fix that

[codecov]

Codecov Report

❌ Patch coverage is 21.42857% with 11 lines in your changes missing coverage. Please review.
✅ Project coverage is 57.27%. Comparing base (0932744) to head (4773502).
⚠️ Report is 86 commits behind head on develop.

Files with missing lines	Patch %	Lines
helpdesk/api/onboarding.py	21.42%	11 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3239      +/-   ##
===========================================
+ Coverage    57.16%   57.27%   +0.11%     
===========================================
  Files          128      129       +1     
  Lines         6172     6235      +63     
===========================================
+ Hits          3528     3571      +43     
- Misses        2644     2664      +20     

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