Display exception notes in tracebacks (#14039) [PEP 678](https://peps.python.org/pep-0678/) introduced the ability to add notes to exception objects. This has been [released in Python 3.11](https://docs.python.org/3/library/exceptions.html#BaseException.add_note) and is currently not implemented in IPython. These changes are fully compatible with older Python versions that don't include PEP 678. Here's a sample test that shows the consistency in Python's stdlib traceback module (test 1) and the difference between Python and IPython's runtimes (test 2): ```python import traceback print('--- test 1 ---') try: raise Exception('Testing notes') except Exception as e: e.add_note('Does this work?') e.add_note('Yes!') traceback.print_exc() print('\n--- test 2 ---') try: raise Exception('Testing notes') except Exception as e: e.add_note('Does this work?') e.add_note('No!') raise ``` When executed with Python 3.11, both notes are displayed in both tracebacks: ``` $ python test.py --- test 1 --- Traceback (most recent call last): File "/app/test.py", line 5, in <module> raise Exception('Testing notes') Exception: Testing notes Does this work? Yes! --- test 2 --- Traceback (most recent call last): File "/app/test.py", line 13, in <module> raise Exception('Testing notes') Exception: Testing notes Does this work? No! ``` In IPython's VerboseTB does not yet handle exception notes: ``` $ ipython test.py --- test 1 --- Traceback (most recent call last): File "/app/test.py", line 5, in <module> raise Exception('Testing notes') Exception: Testing notes Does this work? Yes! --- test 2 --- --------------------------------------------------------------------------- Exception Traceback (most recent call last) File /app/test.py:13 11 print('\n--- test 2 ---') 12 try: ---> 13 raise Exception('Testing notes') 14 except Exception as e: 15 e.add_note('Does this work?') Exception: Testing notes ``` The changes I am suggesting are inspired from implementation of [Lib/traceback.py](https://github.com/python/cpython/blob/main/Lib/traceback.py) (search for `__notes__`) and improvements for dealing with edge cases more nicely in [cpython#103897](https://github.com/python/cpython/pull/103897). Although notes are meant to be strings only, I kept some inspiration from the existing exception handling to ensure that the notes are uncolored and bytes decoded, if there are any. I am definitely open to using a different color if deemed better. For context, `bpython` keeps the notes uncolored, and [Python's tutorial](https://docs.python.org/3/tutorial/errors.html#enriching-exceptions-with-notes) puts them in light gray, like the line numbers. Here's how the test 2 looks like after these changes:  ## :snake: :man_juggling: