Throw warning if `*_beh.tsv` has `onset` and `duration` column

[Remi-Gau]

A file with those columns should probably be an events.tsv in this case.

Issue raised in this PR https://github.com/bids-standard/bids-validator/pull/1367#issue-1029095653

[Remi-Gau]

still an issue with the deno validator

[effigies]

This would be an easy one to write in schema, if you want to make a PR to the spec:

rules.checks.hints.BehavioralOnsetAndDuration:
  issue:
    code: BEH_ONSET_DURATION
    message: Some message
    level: warning
  selectors:
    - suffix == 'beh'
    - extension == '.tsv'
  checks:
    - '!("onset" in columns)'
    - '!("duration" in columns)'