Report warning instead of error if only warnings are returned by hed-validator

[happy5214]

The existing implementation errors out even if only warnings are issued
by hed-validator. This is not desirable, and has been fixed here. A
new issue code has been added, and a new test case has also been added,
though it will not be correct until another change is made upstream.

This is of relatively high severity, as it prevents OpenNeuro from properly validating
any BIDS datasets with HED tag extensions in the sidecar, which generate warnings.

[codecov]

Codecov Report

Merging #1158 (b6dc653) into master (15d9dc5) will increase coverage by 0.02%.
The diff coverage is 88.23%.

@@            Coverage Diff             @@
##           master    #1158      +/-   ##
==========================================
+ Coverage   79.21%   79.23%   +0.02%     
==========================================
  Files          78       78              
  Lines        2593     2601       +8     
  Branches      592      594       +2     
==========================================
+ Hits         2054     2061       +7     
  Misses        400      400              
- Partials      139      140       +1     

Impacted Files	Coverage Δ
bids-validator/validators/events/hed.js	92.66% <88.23%> (-0.41%)	⬇️

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[rwblair]

@happy5214 can you double check my work on the HED issue numbers, due to recent merge I moved them down, wanted to make sure the issue codes in the tests match the correct error messages. Might of been hasty with the merge.

[happy5214]

@happy5214 can you double check my work on the HED issue numbers, due to recent merge I moved them down, wanted to make sure the issue codes in the tests match the correct error messages. Might of been hasty with the merge.

@rwblair Sorry for the late reply. Issue code 209 and 210 were indeed flipped (the error was before the warning in the original, and the issue codes in the actual code reflect that), so that needs to be fixed.