Meshing script improvements

[johannesring]

This PR includes the following meshing scripts improvements:

• Use configargparse to allow to generate a mesh using a config file (use the --config option in vasp-generate-mesh).
• Use pathlib for paths.
• Increase the number of default retries for mesh generation failures (trying to reduce failures on github).

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 70.79646% with 33 lines in your changes are missing coverage. Please review.

Project coverage is 74.65%. Comparing base (b4671c5) to head (c814cc3).
Report is 8 commits behind head on master.

Files	Patch %	Lines
.../automatedPreprocessing/automated_preprocessing.py	69.69%	30 Missing ⚠️
...asp/automatedPreprocessing/preprocessing_common.py	78.57%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #140      +/-   ##
==========================================
- Coverage   74.74%   74.65%   -0.10%     
==========================================
  Files          26       26              
  Lines        3168     3172       +4     
==========================================
  Hits         2368     2368              
- Misses        800      804       +4     

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[keiyamamo]

Looks great!