[ENH] Use caching to speed up limited API exception handling code

[da-woods]

Describe your issue

The current limited API exception handling code creates a minimal code object at each step, and then compiles it.

In principle a single code object could be created on program start-up, which would probably be more efficient

cython/Cython/Utility/Exceptions.c

Line 984 in d3223ed

code_object = Py_CompileString("_getframe()", filename, Py_eval_input);

Note that with a cached version the filename wouldn't be set, so it'd need to be passed to code.update instead.

Comment where this was proposed:
#5550 (comment)

@scoder suggests caching the replace method to skip one step further. That's probably tricky given that it doesn't exist in Python 3.7. However, maybe my ultra-slow Python 3.7 workaround could be refactored into a function and cached in the same way (I'm not too worried about performance in 3.7 since it's really quite old now, but it'd be good to unify it)