Allow configuring minimum TLS version and cipher suites in the ExternalService policy

Requesting a feature to configure the minimum TLS version and cipher suites in the ExternalService policy

This configuration is supported in envoy (https://www.envoyproxy.io/docs/envoy/latest/api-v3/extensions/transport_sockets/tls/v3/common.proto), but is not exposed in the relevant kuma policies.

Not sure if relates to these issues:
https://github.com/kumahq/kuma/issues/4622
https://github.com/kumahq/kuma/issues/4948