chore: OPTIC-1778: Unify and prettify icons

[yyassi-heartex]

we have icons across the different libraries that make up LabelStudio. this PR unifies them to remove duplicates + allows us to standardize them. will also run by design to make sure we update icons to a more modern look

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[codecov]

Codecov Report

Attention: Patch coverage is 57.89474% with 8 lines in your changes missing coverage. Please review.

Project coverage is 77.18%. Comparing base (7487d6e) to head (a365100).
Report is 6 commits behind head on develop.

Files with missing lines	Patch %	Lines
label_studio/core/views.py	33.33%	4 Missing ⚠️
label_studio/users/views.py	66.66%	2 Missing ⚠️
label_studio/core/utils/sentry.py	0.00%	1 Missing ⚠️
...data_manager/actions/predictions_to_annotations.py	80.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #7169      +/-   ##
===========================================
- Coverage    77.19%   77.18%   -0.02%     
===========================================
  Files          187      187              
  Lines        14478    14491      +13     
===========================================
+ Hits         11177    11185       +8     
- Misses        3301     3306       +5     

Flag	Coverage Δ
pytests	77.18% <57.89%> (-0.02%)	⬇️

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