[Feat] Better visualizatio for type annotations

[felixdittrich92]

This PR:

• Add visualization for type annotations
• Fix a bug where it's not possible to reset a type to it's default Cannot remove annotation on an entity #12

TODO:

• some manual tests annotation + re-loading afterwards @t2k-list
• Solve the in-code todo's

[codecov]

Codecov Report

Attention: Patch coverage is 98.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 87.01%. Comparing base (e44868d) to head (a688e7f).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
labeler/views/canvas.py	91.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #14      +/-   ##
==========================================
+ Coverage   80.34%   87.01%   +6.66%     
==========================================
  Files           9        9              
  Lines         870      901      +31     
==========================================
+ Hits          699      784      +85     
+ Misses        171      117      -54     

Flag	Coverage Δ
unittests	87.01% <98.00%> (+6.66%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.