R1:d37153f00304

Make `bin/storage upgrade` and `bin/storage adjust` emit detailed messages if the user has no access to databases

Summary:
Ref T10195. Distinguish between "database does not exist" and "database exists, you just don't have permission to access it".

We can't easily get this information out of INFORMATION_SCHEMA but can just `SHOW TABLES IN ...` every database that looks like it's missing and then look at the error code.

Test Plan:
- Created a user `limited` with limited access.
- Ran `bin/storage…