Moving to platformdirs results in changed paths in AppFS

[tfeldmann]

Before:

>>> fs.__version__
'2.4.15'
>>> fs.open_fs("userconf://test:test", create=True).getsyspath("/")
'/Users/tf/Library/Application Support/test/'

Current master branch:

>>> fs.open_fs("userconf://test:test", create=True).getsyspath("/")
'/Users/tf/Library/Preferences/test/'

I don't think switching to platformdirs is such a good idea at this time. The paths seem to change even in minor version bumps:
tox-dev/platformdirs#47

[althonos]

Oh, damn. I was expecting it to be a simple fork but we may want to go for stability.

[lurch]

ping @felixonmars who contributed #489

[felixonmars]

That's unfortunate :(

It seems it's not a minor version change though, according to replies to the linked issue. Sorry for overlooking it, but I still think this is a valid move because appdirs is indeed abandoned. Perhaps we could delay it to a later major bump?

[althonos]

I've reverted the patch from @felixonmars so that we can wait for a major release before changing it. For PyFilesystem3 we'll want to make the transition to platformdirs, but for now let's keep the things stable.