[PATCH 0 of 3] QUIC ciphers cleanup and CCM support

[Roman Arutyunyan]

Patches 1 & 2 do minor cleanup in encryption code.

Patch 3 adds TLS_AES_128_CCM_SHA256 support to QUIC, which currently is the
only cipher suite not supported by nginx QUIC implementation.  It's disabled
by default in OpenSSL and can be enabled by the following directive:

    ssl_conf_command Ciphersuites TLS_AES_128_CCM_SHA256;