Remove duplicate check that is done on the backend

[athoscouto]

Since we've refined our logic there, and the API returns a nice error we should remove the checks done by the client.

Example:

➜  turso git:(athos/longer-db-names) turso db create aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
Error: could not create database aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa: invalid database name: name must contain between 1 and 52 characters