This commit provides an interface for interacting with a QUIC
integration TLS functionality. The interface is designed in such a way
that allows multiple QUIC integration APIs co-exist in one
codebase. It is modelled after the QUIC integration API found in
BoringSSL/LibreSSL/QuicTLS and thus makes it easy to make an
implementation of the interface for these libraries.
Two implementations are planned:
1. A "native" one that uses the QUIC integration API provided by
crypto libraries (LibreSSL/QuicTLS).
2. A portable compatibility layer.
An API that allows switching between the two at runtime is meant to
aid in unit and interoperability testing.
Artem Boldariev
bcc519081f