Don't trim whitespace after splitting on whitespace for settings.

- The spec doesn't say to do this.
- I've updated regions/space-before-delimiter.vtt to compare to a failing
JSON file as it should actually fail.
Use the same JSON file for good region tests.
Don't set settings if it's an empty string.

This was resulting in behaviour where we were setting settings even
when no value was correctly parsed.
Add bad-delimiter.vtt to region/id tests.

Forgot to add this into the test.js file when it was added.