Pass struct sockaddr to ngtcp2 so that it knows how to deal with
address change in more detailed manner (e.g., just compare IP address
without port).

ACK frame largest_ack field is always the largest packet number even
if the ACK that contains largest_ack has been acknowledged by a remote
endpoint.

This commit fixes the assertion failure which happens when
acknowledgement of earlier packet increases CRYPTO offset.
Previously, the offset is always the first CRYPTO frame offset in the
queue (pktns->crypto.tx.frq).  But passing this into
ngtcp2_pkt_crypto_max_datalen() underestimates the space because
acknowledgement might increase offset; it increases the required space
to serialize offset.

The ngtcp2_cc.c file was using the __builtint_clzll intrinsic which
doesn't exist on MSVC. Added use of the corresponding __lzcnt
intrinsics.

Don't reset cstat->last_tx_pkt_ts which makes assert(earliest_pktns)
fail.

Node.js makes the full `ngtcp2_transport_params` struct available
for storage as a byte array, including any possible padding
in the struct.

Fully initializing the struct with `memset()` makes this deterministic.