Provide record layer callbacks for QUIC.

Provide record layer callbacks for QUIC.

QUIC uses TLS to complete the handshake, however unlike normal TLS it does
not use the TLS record layer, rather it provides its own transport. This
means that we need to intercept all communication between the TLS handshake
and the record layer. This allows TLS handshake message writes to be
directed to QUIC, likewise for TLS handshake message reads. Alerts also
need to be sent via QUIC, plus it needs to be provided with the traffic
keys that are derived by TLS.

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