R1:d32c09de4112

Simplify adding new database patches

Summary:
Currently, to add new migration patches you need to:

- Add a file to `resources/sql/patches/`; then
- add an entry to `src/infrastructure/storage/blahblah/BlahBlahBlah.php`.

The second step isn't actually necessary, and we've been using this system for a long time without any issues arising.

Instead of requiring manual adjustments to the patch list, infer the patch specifications from the files on disk so you don't need to do step 2.

Also, simplify the…