Feature Request: Support Mutual TLS (Client Certificate Authentication)

[MikuSugar]

I'm unable to connect to Neo4j instances that require client certificate authentication. The current TLS configuration options only support:
Server certificate validation via CA certificate
Skipping SSL validation (insecure)
No encryption
This prevents usage of neo4rs in environments requiring mutual TLS authentication.

Request:
Add method to configure client certificate + private key:

ConfigBuilder::mutual_tls(
    client_cert_path: impl AsRef<Path>,
    private_key_path: impl AsRef<Path>
) -> Self

Thank you for considering this enhancement to the driver - it would be greatly appreciated by users requiring enterprise-grade security.