test: use dynamic port instead of common.PORT

Remove common.PORT from, test-net-connect-immediate-destroy,
test-net-options-lookup, test-net-connect-local-error,
test-net-connect-handle-econnrefused, test-net-socket-destroy-twice,
test-net-better-error-messages-port-hostname, test-net-localerror,
to reduce possibility that a dynamic port used in another test will
collide with common.PORT.

Moved test-net-listen-shared-ports, test-net-better-error-messages-port
from tests/parallel to test/sequential

Refs: https://github.com/nodejs/node/issues/12376
PR-URL: https://github.com/nodejs/node/pull/12473


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>