test: track callback invocations

Use `common.mustCall()` and `common.mustNotCall()` to check that
callbacks are invoked the expected number of times in
test-net-listen-shared-ports.

PR-URL: https://github.com/nodejs/node/pull/13010


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>