Add a student id check

[w-lfchen]

This pr aims to add a method to the build tasks that tries to catch students who enter their matriculation number in the studentId field, fail the build and inform them about their mistake.

[Rdeisenroth]

Hmm could we not go for a more exact regex, like [a-z]{2}\d{2}[a-z]{4}?

See https://regex101.com/r/p0Irh8/1

[w-lfchen]

The initial point of this was to simply ensure that no matriculation numbers are entered. I'm not opposed to updating it, but is there a guarantee that all TU-IDs have this format?

[alexstaeding]

A more specific regex would be incorrect. I have seen valid TU-IDs with only one letter (some old ones).

The only commonality I have found is that they all have at least one letter, and this simple check is enough to prevent using the matriculation number instead.

[alexstaeding]

LGTM, but I would still like to test it first before merging