Function build_mariadb_connection_pool 

pub fn build_mariadb_connection_pool(
    host: &str,
    port: u16,
    username: &str,
    password: &str,
    database: Option<&str>,
    ssl_mode: SslMode,
    ssl_root_cert: Option<&str>,
) -> Pool

Build a MariaDB pool with certificate verification for verify-ca and verify-full. Use None for server-wide queries and a concrete database for table access.