Fix reset dataset for 3d model update

[msusag]

Description

This fixes resetting the dataSetId for 3d model updates.

Previously , trying to use ThreeDModelUpdate with a data_set_id.set(None) would lead to a invalid request sent to 3d api.

The dataSetId property is a "primitive" field, not an object, so the fix is to use the correct return type for it, CognitePrimitiveUpdate.

Checklist:

• Tests added/updated.
• Documentation updated. Documentation is generated from docstrings - these must be updated according to your change.
  If a new method has been added it should be referenced in cognite.rst in order to generate docs based on its docstring.
• Changelog updated in CHANGELOG.md.
• Version bumped. If triggering a new release is desired, bump the version number in _version.py and pyproject.toml per semantic versioning.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.06%. Comparing base (774e0d9) to head (ce2f6a4).
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1804      +/-   ##
==========================================
+ Coverage   92.90%   93.06%   +0.15%     
==========================================
  Files         121      121              
  Lines       17700    17700              
==========================================
+ Hits        16444    16472      +28     
+ Misses       1256     1228      -28     

Files	Coverage Δ
cognite/client/_version.py	100.00% <100.00%> (ø)
cognite/client/data_classes/three_d.py	90.49% <100.00%> (+0.45%)	⬆️

... and 7 files with indirect coverage changes

[erlendvollset]

LGTM