Fix bugs in the Nockma prettyprinter and parser

[janmasrovira]

This pr addresses a number of problems.

1. It fixes a bug where paths were annotated as operations rather than paths in the parser.
2. It fixes a bug that happened when unfolding cells in the pretty printer in order to minimize delimiters. It caused the stdlibcall hints to be ignored for the unfolded arguments.
3. In order to properly test this, we can't ignore the hints for the Eq instance, so I've changed that.
4. I've introduced the class NockmaEq for nockma semantic equality. This is used in the evaluator as well as in the semantic tests.
5. I've added a bigger test. I found these bugs while working with this file.