replace get_group_suggestions

- adds **filters argument to get_suggestions()
- passes local=True arg to get_suggestions() for group member suggestions
- removes get_group_suggestions()

Thanks to Mouse for the suggestion to keep the codebase DRY!

bookwyrm/views/group.py

@@ -107,8 +107,9 @@ class FindUsers(View):
         data = {"no_results": not user_results}
 
         if user_results.count() < 5:
-            user_results = list(user_results) + suggested_users.get_group_suggestions(
-                request.user
+            user_results = list(user_results) + suggested_users.get_suggestions(
+                request.user,
+                local=True
             )
 
         group = get_object_or_404(models.Group, id=group_id)