support file names that are not valid UTF-8

[curious-rabbit]

trash-put crashed with UnicodeEncodeError on any file name that is not valid UTF-8. Such names are legal on Linux.

With this patch the Path value is percent-encoded from the raw bytes and decoded back the same way, so put, list, rm and restore keep the exact name. Output code escapes bytes that a stream can not take, so trash-list and trash-restore print such names instead of crashing.

[andreafrancia]

Good idea, thank you for the PR. I'll review this later because I've finished my time.

If you want check out if you followed the usual guidelines:

• Please add behaviour explaining shell example. Maybe, if you want, add them as a feature description in markdown somewhere under docs/
• The ensure that you used class based pytest tests.
• Provide at least one test calling entire command (but from the inside) that uses Fakes.
• Remove repetitions you see it.

[curious-rabbit]

$ touch "$(printf 'bad\xffname')"
$ trash-put bad*name
Traceback (most recent call last):
  ...
UnicodeEncodeError: 'utf-8' codec can't encode byte 0xff in position 3