Test dir operations on WSL

[warpdesign]

• makedir
• copy/paste
• rename
• delete

Some edge cases that should be handled:

• some characters that are forbidden in Windows can be used in Linux filenames, so any function checking for invalid chars should use Unix rules when working on a WSL folder (eg. rename, create directory,...)
• when copying files from WSL to Windows, forbidden characters should (could?) be replaced
• check that path text input allows to enter a path containing windows forbidden characters if it's a WSL path

Note

Windows Explorer doesn't seem to handle these cases at all: microsoft/WSL#5516 & microsoft/WSL#5515 and the Microsoft dev team appears to be fine with that.

This is not good enough for react-explorer that should handle most cases.