Update the schema checks of the `wait-for-deps` pattern to be aware
of all migrations, by directly comparing the entries in the appropriate
directories in the application to the table within the database.

This replaces the previous implementation that looked at the latest dated
migration in the codebase versus the database. That check was naive, and
fast, but problematic for several reasons.

This should address multiple factors:
- support concerns of migrations being milestone ordered
- migrations dated in the past
- failed intermediate migrations, from previous upgrades

Changelog: fixed


Closes #2024