Remove deprecated User/Robot/Session completely

[Affie]

close #1148

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 72.98%. Comparing base (7823fe4) to head (1637fc6).
Report is 1 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1150      +/-   ##
===========================================
- Coverage    73.20%   72.98%   -0.22%     
===========================================
  Files           29       29              
  Lines         2474     2421      -53     
===========================================
- Hits          1811     1767      -44     
+ Misses         663      654       -9     

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