Support Cipher Suite Allow List

[anrossi]

Add support to Schannel and OpenSSL to explicitly indicate which TLS1.3 cipher suites to use. Closes #109

[rzikm]

Hi, @anrossi, was there a specific reason to not support TLS_AES_128_CCM_SHA256? it is listed among the TLS 1.3 cipher suites and QUIC-TLS RFC only prohibits TLS_AES_128_CCM_8_SHA256:

QUIC can use any of the cipher suites defined in [TLS13] with the
exception of TLS_AES_128_CCM_8_SHA256. A cipher suite MUST NOT be
negotiated unless a header protection scheme is defined for the
cipher suite. This document defines a header protection scheme for
all cipher suites defined in [TLS13] aside from
TLS_AES_128_CCM_8_SHA256. These cipher suites have a 16-byte
authentication tag and produce an output 16 bytes larger than their
input.

[anrossi]

@rzikm Historically, we've supported AES-GCM and ChaCha20-Poly1305 because those were the algorithms in both TLS libraries we were originally using. There wasn't a pressing need to support AES-CCM, so we haven't done the crypto work to add support.
If someone came to us asking to support AES-CCM, or had a PR adding support, we'd do the work/accept it.