quic: cleanup QuicSocketFlags, used shared state struct

Some of the flags were no longer being used.

Switched to use an AliasedStruct for shared state to avoid
extraneous expensive JS=>C++ calls.

Removed unused QuicSocket option

PR-URL: https://github.com/nodejs/node/pull/34247


Reviewed-By: Anna Henningsen <anna@addaleax.net>