[FE-6169] Support Shorthand Region Groups

[henryfauna]

Ticket(s): FE-6169

Problem

You must use the region groups that the account api expects as input to the --database arg. eg. --database us-std/my-database. We do not often expose the name us-std to customers and it will likely be more natural to use --database us/my-database as that is what is presented in the dashboard.

Solution

Standardize region groups before they are passed to the account API. This allows the usage of --database us-std/my-database or --database us/my-database.

Result

You can use whatever region group reference you prefer.

Testing

Updated existing tests.