reloader can use sys.orig_argv to get exact command

[davidism]

sys.orig_argv, added in Python 3.10, contains the exact command line used to start the python command. It does not modify -m name into /path/to/name.py, and keeps arguments like -X dev. The reloader can use this instead of all the reconstructing it does right now.

[davidism]

This would also happen to fix #2588, where poetry run creates a python -c 'import...' command (somewhat incorrectly, but still). There's no way for the existing code to work with this, sys.argv only sees "-c", not the rest of the command.

[delucca]

@davidism thanks for all your work!

After this PR is released, I assume I can simply update Flask and it will allow me to use Poetry even if they insist in not fixing the unexpected mutation of sys.argv?