Refactoring

* moves updating of shared access users into ShareableObjectMixin
* renames ShareInterventionModalForm to ShareModalForm since it's used for EMA and eco accounts as well

intervention/models/intervention.py

@@ -284,25 +284,6 @@ class Intervention(BaseObject, ShareableObjectMixin, RecordableObjectMixin, Chec
             )
         return deduction
 
-    def update_sharing_user(self, form):
-        """ Adds a new user with shared access to the intervention
-
-        Args:
-            form (ShareInterventionModalForm): The form holding the data
-
-        Returns:
-
-        """
-        form_data = form.cleaned_data
-
-        keep_accessing_users = form_data["users"]
-        new_accessing_users = list(form_data["user_select"].values_list("id", flat=True))
-        accessing_users = keep_accessing_users + new_accessing_users
-        users = User.objects.filter(
-            id__in=accessing_users
-        )
-        self.share_with_list(users)
-
 
 class InterventionDocument(AbstractDocument):
     """