- `tls.incoming`: applies to the inbound mTLS targeting the public
listener on `connect-proxy` and `terminating-gateway` envoy instances
- `tls.outgoing`: applies to the outbound mTLS dialing upstreams from
`connect-proxy` and `ingress-gateway` envoy instances
Fixes#11966
There is no interaction between these handlers, so splitting them into separate files
makes it easier to discover the full implementation of each kindHandler.