feat: set python exception if an error happens in a js callback

[sigmaSd]

This changes errors like this

SystemError: <built-in method JSCallback:anonymous of NoneType object at 0x7f988b6f8bd0> returned NULL without setting an exception

To something more useful

RuntimeError: JS Callback Error: PythonError: Must be number, not str

[sigmaSd]

this last commit 0eed1e5 change

RuntimeError: JS Callback Error: PythonError: Must be number, not str

The above exception was the direct cause of the following exception:

SystemError: <built-in method JSCallback:anonymous of NoneType object at 0x7fc7e6cf8bd0> returned a result with an exception set

to just

RuntimeError: JS Callback Error: PythonError: Must be number, not str

I think the first one just have extra noise