feat(CodeEditor): support forwarding props to pre element

[tujoworker]

This PR supports forwarding of props to the pre element. This allows to set e.g. unique ID for using a label. Or also aria-label will do it (Its important that it is set to the actual element) and not on a wrapper div.

Test plan

In order to test this component properly, I added @testing-library/react including tests for cases I think needed to be tested.