[cli] Feature: Add a baseline command to fake apply migrations up to a certain version

[mehcode]

See #639 (comment)

[abonander]

I don't know if we want it to be part of the baseline command or not but when developing a feature that modifies the database I realize I tend to do the following:

• Write and run a migration for the schema changes I anticipate will be needed (new table, new columns in existing table, etc.)
• Begin developing the feature
• Realize I need to make more changes to the schema
• Since the migration I just wrote hasn't been pushed to production, I prefer to modify it in-place and manually update the DB

But if the application uses sqlx::migrate!() it will die on startup because the migrations are out of sync with the database.

It's not that hard to just do openssl dgst -sha384 <migration file> and then update the hash in the _sqlx_migrations table but it would be nice to have a single command to do both.

I'm thinking we might want it to be separate from the baseline command because it's replacing the hash of a migration that's already run, but I'm not sure what I'd call it. sqlx migrate override?

[abonander]

@mehcode

# mark <version> as applied if not already (error on hash mismatch)
sqlx migrate override --just=<version>

# mark <version> as applied, overwrite hash
sqlx migrate override -f --just=version

# mark all migrations up to and including <version> as applied (error on hash mismatch)
sqlx migrate override --up-to=<version>

# mark all migrations up to and including <version> as applied, overwrite mismatched hashes
sqlx migrate override -f --up-to=<version>

# mark all migrations as applied (error on hash mismatch)
sqlx migrate override --all

# mark all migrations as applied, overwrite mismatched hashes
sqlx migrate override -f --all

# starts a dialogue asking the user to select the target migration version (defaulting to latest), all/upto/just that version, and attempt to process the selected versions, asking to quit/skip/force on each that mismatches
sqlx migrate override