Find a solution for "problems" in AST, passes and parsing

[oxisto]

Following the discussion in #1663 (comment), we want to have a solution for all kind of "problems", either from parsing/translating the AST, as well as executing things in the passes.

These "problems" should have different types and probably be stored in either the translation result or context, so that we can access them after everything runs for debugging. This would also allows us to have some kind of information how "good" the translation / passes were.

[konradweiss]

I like the idea of having ProblemNodes in the AST and additional ProblemNodes in the TranslationResult for the more general problems. However, when we have one of these more general problems, do we want it to reference a "location" or another node that is relevant to the problem? For example, a reference that could not be resolved. Or have one general ProblemNode("Reference could not be resolved") with edges to all appearances of that problem?