bin/verify-exercises-in-docker script

[keiravillekode]

Adapted from

https://github.com/exercism/generic-track/blob/main/bin/verify-exercises-in-docker

https://github.com/exercism/free-pascal/blob/main/bin/verify-exercises-in-docker

[keiravillekode]

This is a convenient script for checking if an exercise's example solution passes the tests using the test runner, as opposed to using the locally installed v.

It is also a convenient way to check if all the exercises pass a proposed test runner upgrade: build the docker image for the new test runner, and call this script with -i <image>