chore: Add some more Label Studio SDK unit tests

[jombooth]

Describe the reason for change

(link to issue, supportive screenshots etc.)

Test a bunch more Label Studio SDK functionality + update to latest state of label_studio_sdk repo. This work is part of our Label Studio SDK productionization effort.

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (3f3f75c) 76.11% compared to head (8286a69) 76.21%.
Report is 7 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #5149      +/-   ##
===========================================
+ Coverage    76.11%   76.21%   +0.09%     
===========================================
  Files          154      154              
  Lines        12792    12792              
===========================================
+ Hits          9737     9749      +12     
+ Misses        3055     3043      -12     

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