✨(backend) annotate number of accesses on documents

The new UI will display the number of accesses on each document.

/!\ Once team accesses will be used, this will not represent the number
    of people with access anymore and will have to be improved by
    computing the number of people in each team.

src/backend/core/api/viewsets.py

@@ -1,4 +1,5 @@
 """API endpoints"""
+# pylint: disable=too-many-lines
 
 import re
 import uuid
@@ -10,6 +11,7 @@ from django.contrib.postgres.search import TrigramSimilarity
 from django.core.exceptions import ValidationError
 from django.core.files.storage import default_storage
 from django.db.models import (
+    Count,
     Exists,
     Min,
     OuterRef,
@@ -334,6 +336,9 @@ class DocumentViewSet(
         queryset = super().get_queryset()
         user = self.request.user
 
+        # Annotate the number of accesses associated with each document
+        queryset = queryset.annotate(nb_accesses=Count("accesses", distinct=True))
+
         if not user.is_authenticated:
             # If the user is not authenticated, annotate `is_favorite` as False
             return queryset.annotate(is_favorite=Value(False))
@@ -360,6 +365,7 @@ class DocumentViewSet(
         """Restrict resources returned by the list endpoint"""
         queryset = self.filter_queryset(self.get_queryset())
         user = self.request.user
+
         if user.is_authenticated:
             queryset = queryset.filter(
                 Q(accesses__user=user)