Improve UX when no other ZenFusion module is available

[rdoursenaud]

This module is a technical dependency to other modules and don't offer any user feature by itself.
It's built as a module so that the code can be shared amongst other modules.

When installed without any other modules, it issues a "NoScope" error that is not very helpful in understanding the problem.
Improve the message by providing to the user the information that he needs to install at least one other module from the ZenFusion family.

[rdoursenaud]

Also make it more obvious in the dolistore entry.