test: dynamic port in parallel cluster tests

Removed common.PORT from test-cluster-message,
test-cluster-server-restart-none, test-cluster-server-restart-rr
and test-cluster-shared-handle-bind-error to eliminate the
possibility that a dynamic port used in another test will collide
with common.PORT.

PR-URL: https://github.com/nodejs/node/pull/12584
Ref: https://github.com/nodejs/node/issues/12376


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>