Add an API for other QUIC stacks to use our TLS implementation

Add an API for other QUIC stacks to use our TLS implementation

We provide some callbacks for third party QUIC stacks to use in order
to be able to reuse the OpenSSL TLS implementation in that stack. This is
essentially a thin wrapper around the same API that OpenSSL's own QUIC
stack uses in order to integrate TLS.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/26683)