Keycloak client: Support TLS certificates issued by trusted certificate authorities.

When Web/HTTP clients send requests proxied by AWS application load balancers, there is no need for a trust store containing the ALB's certificate, as all ALBs utilize "Public Trusted Certificates" from trusted CAs. In these scenarios, configure Web/HTTP clients with TLS enabled, omitting the trust store path, password, and type, etc.

Enhance the setup of Web/HTTP clients to support "Public Trusted Certificates" without requiring a certificate and a trust store.