Restore File::unique() helper

[damsfx]

Restore :

• 68bb7ac (partially)
• 76a4302

[mjauvin]

@damsfx you also need to add the method signature to the File facade (winter/storm/src/Support/Facades/File.php)

[damsfx]

@damsfx you also need to add the method signature to the File facade (winter/storm/src/Support/Facades/File.php)

@mjauvin Just done it!
However, having done this on the develop branch was an error ... I'm always afraid in this case of not being in line with the winter repo.