Restore help "right"

### What does it do ?

Restores the help permission into the main menu.

### Why is it needed ?

When the `help` permission is disabled/removed, users are no able to access the help page.
Before this, the menu would still display the "help" link, leading the users to a beautiful "access denied" message.

### Steps to reproduce issue

* remove the "help" permission to any non 'sudo' user
* log in as that user, see the help menu (icon) is present and leads you to an "access denied" message

### Related issue(s)/PR(s)

This a just a small part of issues mentioned in #11622