Change person schema to export count of unread notifications

aleksis/core/schema/person.py

 import graphene
+from django.utils import timezone
 from graphene_django import DjangoObjectType
 from graphene_django.forms.mutation import DjangoModelFormMutation
 
@@ -11,6 +12,7 @@ class PersonType(DjangoObjectType):
         model = Person
 
     full_name = graphene.Field(graphene.String)
+    unread_notifications_count = graphene.Field(graphene.Int)
 
     def resolve_full_name(root: Person, info, **kwargs):
         return root.full_name