feat: Allow editor role to write to shared graph

The shared graph contains, among others, the (legal) names of municipalities and
provinces. So far their names were not modifiable in OP. This change allows
these names to be modified in that graph by the users with the appropriate role.

config/authorization/config.ex

@@ -128,6 +128,12 @@ defmodule Acl.UserGroups.Config do
             constraint: %ResourceConstraint{
               resource_types: @org_type ++ @error_type
             }
+          },
+          %GraphSpec{
+            graph: "http://mu.semte.ch/graphs/shared",
+            constraint: %ResourceConstraint{
+              resource_types: @org_type
+            }
           }
         ]
       },