net: refactor Server.prototype.listen

This PR simplifies Server.prototype.listen, removing some redundancy and
inconsistency. Because listen and connect have a similar function signature,
normalizeConnectArgs can be reused for listen.
listenAfterLookup renamed to lookupAndListen for consistency with
lookupAndConnect, and moved out of Server.prototype.listen.

PR-URL: https://github.com/nodejs/node/pull/4039


Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Glen Keane <glenkeane.94@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>