Add definitions check to CI #7918

New Feature / Enhancement Checklist

• I am not disclosing a vulnerability.
• I am not just asking a question.
• I have searched through existing issues.

Current Limitation

There is currently no way to auto-detect whether definitions (Parse Server options) were correctly added via auto-generation by running npm run definitions, or whether they were incorrectly manually added.

Feature / Enhancement Description

Add CI check that runs npm run definitions and compares the output to the definitions file submitted in a PR. If they don't match, then fail the CI.

Example Use Case

n/a

Alternatives / Workarounds

Manual check.