test: do not race connection and rejection

Existing code assumed that the server completed the handshake before the
client rejected the certificate, and destroyed the socket. This
assumption is fragile, remove it, and instead check explicitly that data
can or cannot be exchanged via TLS, whichever is expected.

PR-URL: https://github.com/nodejs/node/pull/25508


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>