Clean parsing of optional config.yaml data

[abhaasgoyal]

Fixes #234, #239

Merge Message

• Parse config.yaml and fill all optional data before validation. We assume that using keys in config would never lead to KeyError in other modules after validation.
• Correction for validating config schema:
  • Change multiprocessing to multiprocess to match documentation
  • Regex match forwalltime to match single digit numbers
  • Remove Deprecation warning for (?i) flag at the start for mem

[codecov]

Codecov Report

Attention: 5 lines in your changes are missing coverage. Please review.

Comparison is base (d1d6280) 58.22% compared to head (2efcd48) 59.13%.
Report is 1 commits behind head on main.

Files	Patch %	Lines
benchcab/benchcab.py	0.00%	4 Missing ⚠️
tests/test_config.py	97.36%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #238      +/-   ##
==========================================
+ Coverage   58.22%   59.13%   +0.90%     
==========================================
  Files          29       29              
  Lines        2109     2129      +20     
==========================================
+ Hits         1228     1259      +31     
+ Misses        881      870      -11     

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[ccarouge]

A couple of minor changes and some documentation/linting issues to solve.
Re-ask for a review via GitHub when you are done.

[ccarouge]

A few things I missed. And where are the tests for read_optional_data?

[ccarouge]

Actually, can we rename read_optional_data? I don't like the use of data here. In the doc, we are using key for the entries in the config file maybe that's the best choice.

[ccarouge]

It looks good. I'm requesting changes because of the fixtures for the tests but the other comments are minor.

[ccarouge]

All good. A couple of simple suggestions.