Provide an easy way to change / extend menus

We need some way to specify which views are available for a certain admin.

It might make sense to have something like a get_menu_entries() method on the
admin instance that returns the urls + verbose names for all available views.
This would be used to build menus, dashboards and these kinds of things.

Also when extending the admin you could just add a new menu entry for additional custom views.

The issue does not name files or tests. Start by locating the admin instance and its current menu or dashboard handling, then determine how a get_menu_entries() API could expose URLs and verbose names for available views. Done means admins can change or extend menu entries for custom views.

Written by the indexing model from the issue text.