Introduce track_caller for panicing methods of ExecuteKernel

[9SMTM6]

This adds track_caller attributes to improve debugging for library users, as suggested in #49.

I did test it in my own project, worked as expected, for both the panic! and also the assert! calls.

• https://doc.rust-lang.org/stable/reference/attributes/codegen.html?highlight=track_call#the-track_caller-attribute
• for future reference, if any path in the library panics all that needs to be done for the panic to show the location in the users code is mark all functions along the call-stack with track_caller
• I did try and test the behavior, (with unit-tests) because I can be masocistic like that, but decided to give up on it, I would have to manually temporarily switch the panic_hook during testing, if that even works. Ugly, and if it happens to work its not guaranteed to continue working.