Improved formatting for ListLiterals in multi dimensional lists

[eyn9xwy]

This PR fixes an issue with the layout of list literals by using a new line for each imbricated list element.

#1421

[alexanderpann]

Not sure what others think about it, but sometimes it feels like there are too many line breaks after this change and I am not sure if this helps with readability. Another option would be to only use breaks when the list literal contains a certain number of elements e.g. 3 or 5 or rather create a new concept for those matrix-style initialisations.

vs

[eyn9xwy]

Fair point, but in our case the lists may look something like this:

There's no apparent structure, so I don't think a static rule like "line break after n elements" will do the trick.
I'll talk to my team about creating a new concept.