Please add support for TLS Encrypted Client Hello

• Championed by the EFF: https://www.eff.org/deeplinks/2018/09/esni-privacy-protecting-upgrade-https
• Deployed by Cloudflare: https://blog.cloudflare.com/esni/
• Cloudflare's technical details post: https://blog.cloudflare.com/encrypted-sni/
• Supported by Firefox: https://blog.mozilla.org/security/2018/10/18/encrypted-sni-comes-to-firefox-nightly/
• Supported by NSS: https://bugzilla.mozilla.org/show_bug.cgi?id=1495120
• Work in Progress in picotls: Encrypted SNI h2o/picotls#155

Previous ticket for ESNI was not recreated after being closed, so here it is.

List taken from the openssl issue.