test: create shared runBenchmark function

Mostly shared/duplicated logic between all benchmark test files, so
creating a new common module to store it.

PR-URL: https://github.com/nodejs/node/pull/15004


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>