Bug description:
Project folder names shouldn't contain charcaters such as "/".
When creating a new folder, Ametys prevents the user from using such characters.
However, Ametys doesn't prevent users from modifying existing folders and using charcaters such as "/".

Steps to reproduce bug:
-Create a folder in the documents section of any project
-Modify the name of the folder so it contains illegal charcaters

Consequence of the bug:
It makes it impossible to access the files within the folder