fix: config option flags sometimes not parsed correctly

[phm07]

See #845 for a description of the error

While parsing the config's FlagSet, if the parser reached a flag that was not a config option, it would terminate early and return an unknown flag error. Since the error was ignored silently, this behavior was not apparent to the user.

This PR fixes this behavior by using the ParseErrorsWhitelist to allow unknown flags in the config's FlagSet. This also means we can now return any other parsing errors properly instead of ignoring them.

Fixes #845

[codecov]

Codecov Report

Attention: Patch coverage is 62.50000% with 3 lines in your changes missing coverage. Please review.

Project coverage is 70.11%. Comparing base (69fdaf0) to head (aed999d).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/state/config/config.go	62.50%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1025      +/-   ##
==========================================
- Coverage   70.18%   70.11%   -0.07%     
==========================================
  Files         246      246              
  Lines       10815    10820       +5     
==========================================
- Hits         7590     7586       -4     
- Misses       2547     2553       +6     
- Partials      678      681       +3     

Flag	Coverage Δ
e2e	46.82% <62.50%> (-0.09%)	⬇️
unit	63.59% <62.50%> (-0.07%)	⬇️

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[jooola]

Could we have a test to ensure the behavior is correct?