fix: filter wfxctl job query by group

[amvasil-v]

Description

Fix wfxctl --group filtering option so it correctly accepts a list of group names.
Currently the group filter is ignored because of the wrong type of the argument.
Add bash CLI tests for wfxctl --group option.

Issues Addressed

List and link all the issues addressed by this PR.

Change Type

Please select the relevant options:

• Bug fix (non-breaking change that resolves an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist

• I have read the CONTRIBUTING document.
• My changes adhere to the established code style, patterns, and best practices.
• I have added tests that demonstrate the effectiveness of my changes.
• I have updated the documentation accordingly (if applicable).
• I have added an entry in the CHANGELOG to document my changes (if applicable).

[codecov]

Codecov Report

Merging #58 (4074629) into main (4d3f091) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main      #58   +/-   ##
=======================================
  Coverage   78.79%   78.79%           
=======================================
  Files          80       80           
  Lines        3023     3023           
=======================================
  Hits         2382     2382           
  Misses        464      464           
  Partials      177      177           

Files	Coverage Δ
cmd/wfxctl/cmd/job/query/query.go	80.43% <100.00%> (ø)

[michaeladler]

Thanks for your contribution!