Tls libtrust auth

Turns on TLS by default and uses public keys to authenticate access.

- This PR still may require further testing and input on the user experience.
- FSNotify support has not been added to detect changes to authorized_keys
- Depends on #8112

@bfirsh please review and comment on whether this is missing anything needed
Does that mean we read certs from a possible insecure tls connection?