Fix filter for groups and courses to show the right data

- only within current school term
- no duplicates
- unique ID for every element

aleksis/apps/alsijil/frontend/components/coursebook/CoursebookFilters.vue

@@ -3,6 +3,7 @@
     <v-autocomplete
       :items="selectable"
       item-text="name"
+      :item-value="(item) => `${item.__typename}-${item.id}`"
       clearable
       return-object
       filled

aleksis/apps/alsijil/schema/__init__.py

@@ -122,8 +122,10 @@ class Query(graphene.ObjectType):
         else:
             raise PermissionDenied()
 
-        return Group.objects.filter(
-            Q(members=person) | Q(owners=person) | Q(parent_groups__owners=person)
+        return (
+            Group.objects.for_current_school_term_or_all()
+            .filter(Q(members=person) | Q(owners=person) | Q(parent_groups__owners=person))
+            .distinct()
         )
 
     @staticmethod
@@ -136,13 +138,15 @@ class Query(graphene.ObjectType):
             person = info.context.user.person
         else:
             raise PermissionDenied()
-
         return Course.objects.filter(
-            Q(teachers=person)
-            | Q(groups__members=person)
-            | Q(groups__owners=person)
-            | Q(groups__parent_groups__owners=person)
-        )
+            (
+                Q(teachers=person)
+                | Q(groups__members=person)
+                | Q(groups__owners=person)
+                | Q(groups__parent_groups__owners=person)
+            )
+            & Q(groups__in=Group.objects.for_current_school_term_or_all())
+        ).distinct()
 
     @staticmethod
     def resolve_lessons_for_persons(