Feature
https://github.com/RustPython/RustPython/blob/main/vm/src/stdlib/builtins.rs#L899-L919
We should compare between class (invoked by metaclass) and classcell's internal contents before exiting __build_class__
At now we manually set classcell's internal contents with class, but this should be done in type.__new__
Python Documentation
Related test cases
test_super.py
test___classcell___overwrite
test___classcell___missing
test___classcell___wrong_cell
test___class___new
test___class___delayed