Support server version detection for MSSQL+MySQL #374

What problem are you facing?

In 749c80a we added the ability to filter privileges based on PostgreSQL server version (e.g., the MAINTAIN privilege is only available in PG 17+).

The reconcilers call GetServerVersion() during Connect() and pass the version to privilege expansion functions.

Both MySQL and MSSQL had GetServerVersion added to satisfy the xsql.DB interface, but the implementations were no-ops.

How could Crossplane help solve your problem?

Real GetServerVersion implementations to allow a similar experience for MSSQL and MySQL.