frontend/OpenFHEBackend: functions with same name cause issues

[AlexanderViand]

While putting together some tests, I had two @compile() def foo(...): ... functions (in separate tests cases) and noticed the first test would get the result I expected from the second test. This goes away when I rename one to another name. Since we use the function name for a bunch of things (pybind module, etc), I'm guessing there's some fun interactions between the two going on somewhere.

Tagging @j2kun for when he's back :)