support certificat in sslmode

### What problem are you facing?

We want to connect to a gcp cloud sql instance via IP. We need to use SSL for the connection


### How could Crossplane help solve your problem?

I could not find any support for something like sslmode=verfiy-full&sslrootcertificate=cert.pem in the code. It would be great to have this option and another kubernetes secret reference in the config for the certificate

