[idea] filter configurations by relationship with a specific template

[cappe87]

it may be useful to have a way to filter configurations that have a relationship with a specific template

[nemesifier]

@cappe87 adding the filter is easier than I thought. It's just a matter of adding templatesin list_filters of AbstractConfigAdmin:
https://github.com/openwisp/django-netjsonconfig/blob/master/django_netjsonconfig/base/admin.py#L214

The hard part is in openwisp-controller: the filter should display only templates of organizations that the current user has access to (only superusers see everything).

[nemesifier]

I created an issue also on openwisp/openwisp-controller#2.

[nemesifier]

Closed by 90d4e99