Support for TLS ECH (Encrypted Client Hello)

*Title*: Add support for accepting encrypted Client Hellos

*Description*:
SNI information in the initial TLS handshake is not encrypted by default, ECH solves this issue.

Browsers support [RFC 9849 - TLS Encrypted Client Hello](https://www.rfc-editor.org/rfc/rfc9849.html) already for some time: Firefox since version 118, [Chrome since 117](https://chromestatus.com/feature/6196703843581952).

Some servers also support ECH, e.g. [Nginx](https://github.com/nginx/nginx/pull/840) and [haproxy](https://github.com/haproxy/haproxy/issues/1924).

[optional *Relevant Links*:]
>Any extra documentation required to understand the issue.

- [Understand Encrypted Client Hello (ECH)](https://support.mozilla.org/en-US/kb/understand-encrypted-client-hello)
- [Encrypted Client Hello - the last puzzle piece to privacy](https://blog.cloudflare.com/announcing-encrypted-client-hello/)