Write documentation for codecs.escape_encode() and codecs.escape_decode()

[malemburg]

Those APIs are used by pickle and provide a great way to handle escaped bytes sequences in much the same way as str(bytes)/repr(bytes) works.

In Python 2, these were used by the string_escape codec, but that was removed for some reason. Perhaps we should revive this as bytes_escape codec.

Example:
codecs.escape_decode(str(b))[0][2:-1] == b

Linked PRs

• gh-136278: Add documentation for codecs.escape_encode() and codecs.escape_decode() #136310
• gh-136278: Document codecs.escape_encode() and codecs.escape_decode() #136314