net: allow missing callback for Socket.connect

Arguments of Socket.prototype.connect should be also normalized,
causing error when called without callback.

Changed Socket.prototype.connect's code same as net.connect and added
test.

Fixes: https://github.com/nodejs/node/issues/11761
PR-URL: https://github.com/nodejs/node/pull/11762


Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>