Make item count in Dashboar visible to every pilot

[wellemut]

Problem

The "Dashboard" button of the ofdb results in an error message for normal acountants

Test it here: https://openfairdb.org/dashboard

Solution

• A. Make the statistics visible to every user but hide the User Management, if its not a super admin
• B. Hide the Button completly, so that nobody can see it (Helmut has to remebmer the URL for Usermanagement)
• C. Implement all Entry-Moderation directly in the frontend of kvm. (Backend only for super admins needed.) https://github.com/kartevonmorgen/kartevonmorgen.ts/issues/152

Suggestions:

If A is not done within one hour, we should directly implement C (frontend)