test: use random ports where possible
This is a backport of https://github.com/nodejs/node/pull/7045.
CI just to be sure, due to the number of changes: https://ci.nodejs.org/job/node-test-pull-request/3273/
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
This is a backport of https://github.com/nodejs/node/pull/7045.
CI just to be sure, due to the number of changes: https://ci.nodejs.org/job/node-test-pull-request/3273/