feat(generate_classes.py): allow excluding components

[wpbonelli]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 16.66667% with 5 lines in your changes missing coverage. Please review.

Project coverage is 76.3%. Comparing base (bb9824e) to head (eb2f590).
Report is 53 commits behind head on develop.

Files with missing lines	Patch %	Lines
flopy/mf6/utils/generate_classes.py	16.6%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##           develop   #2447     +/-   ##
=========================================
+ Coverage     68.4%   76.3%   +7.8%     
=========================================
  Files          294     293      -1     
  Lines        59390   60124    +734     
=========================================
+ Hits         40652   45880   +5228     
+ Misses       18738   14244   -4494     

Files with missing lines	Coverage Δ
flopy/mf6/utils/generate_classes.py	17.3% <16.6%> (-0.5%)	⬇️

... and 249 files with indirect coverage changes