full e-stepper: heap objects of full Python in the e-stepper protocol #179

Extend @sourceacademy/common-e-stepper (language-agnostic) with the heap objects of full Python: tuple, dict, class, instance, bound method, iterator, generator, exception. Draw them in the plugin's own diagram.

Design note: https://github.com/source-academy/py-slang/blob/main/docs/full-e-stepper.md (PR source-academy/py-slang#555). Part of the full-e-stepper project.