Added (useful) error for using lists in filter by level

[Rlamboll]

…rbidden column.

Please confirm that this PR has done the following:

• [x] Tests Added
• [x] Documentation Added
• [x] Name of contributors Added to AUTHORS.rst
• [x] Description in RELEASE_NOTES.md Added

Adding to RELEASE_NOTES.md (remove section after adding to RELEASE_NOTES.md)

Please add a single line in the release notes similar to the following:

- (#XX)[http://link-to-pr.com] Added feature which does something

Description of PR

Please describe the changes introduced by this PR.

[codecov[bot]]

Codecov Report

Merging #713 (cb5c0b1) into main (83b7542) will increase coverage by 0.0%. The diff coverage is 100.0%.

@@          Coverage Diff          @@
##            main    #713   +/-   ##
=====================================
  Coverage   94.9%   94.9%           
=====================================
  Files         58      58           
  Lines       5909    5914    +5     
=====================================
+ Hits        5609    5614    +5     
  Misses       300     300           

Impacted Files	Coverage Δ
pyam/_style.py	49.1% <ø> (ø)
pyam/utils.py	91.7% <100.0%> (+<0.1%)	:arrow_up:
tests/test_core.py	100.0% <100.0%> (ø)

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[Rlamboll]

@danielhuppmann The tests indicate a problem with the cached dependencies, I don't think this is related to my changes though?

[danielhuppmann]

@danielhuppmann The tests indicate a problem with the cached dependencies, I don't think this is related to my changes though?

Fixed via #714

[danielhuppmann]

Closed and reopened to re-trigger tests after fixing the dependency issues

[danielhuppmann]

Still failing, maybe need to rebase?

[Rlamboll]

OK, looks like the rebase fixed it!