fix: import collision for types

[Ithanil]

This is basically a new submission of #3, fixing the (not fixed) issue #2

From Python 3.11 onwards, a naming collision of the types.py file with the stdlib module types prevents execution of the code. See the comments in #3 for multiple re-reports of the issue.

This is fixed by a simple renaming of the file from types.py to eval_types.py.