Implement support for HED specification's JSON test suite

[happy5214]

The HED specification provides a JSON-based test suite at https://github.com/hed-standard/hed-specification/tree/master/tests, which provides a set of example data (including strings, sidecars, TSV files, and combinations thereof), which should pass, and expected errors for those that should fail. This validator should eventually support validating against this test suite in an automated fashion. This would not directly affect the validator's built-in test modules.

The validation could be implemented in two stages:

1. Simple pass-fail validation (without regard to the exact error code).
2. Validating the actual error code.

[VisLab]

At this point, #1 is the most important. The hed-python GitHub actions run the tests against the spec JSON as a separate step. We could do it that way for hed-javascript. As the spec is iterated and tests are added (as happened recently with tests for the deprecatedFrom warnings), we would not expect the hed-javascript to pass right away, but this is because it requires a new feature to be implemented.