https: add extra options to Agent#getName()

Adds the remaining options from tls.createSecureContext() to the
string generated by Agent#getName(). This allows https.request() to
accept the options and generate unique sockets appropriately.

PR-URL: https://github.com/nodejs/node/pull/16402


Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>