✨(backend) allow filtering on document titles

This is the minimal and fast search feature, while we are working on
a full text search based on opensearch. For the moment we only search
on the title of the document.

src/backend/core/api/filters.py

@@ -18,10 +18,13 @@ class DocumentFilter(django_filters.FilterSet):
     is_favorite = django_filters.BooleanFilter(
         method="filter_is_favorite", label=_("Favorite")
     )
+    title = django_filters.CharFilter(
+        field_name="title", lookup_expr="icontains", label=_("Title")
+    )
 
     class Meta:
         model = models.Document
-        fields = ["is_creator_me", "is_favorite", "link_reach"]
+        fields = ["is_creator_me", "is_favorite", "link_reach", "title"]
 
     # pylint: disable=unused-argument
     def filter_is_creator_me(self, queryset, name, value):

src/backend/core/api/viewsets.py

@@ -326,10 +326,11 @@ class DocumentViewSet(
         - `is_creator_me=false`: Returns documents created by other users.
         - `is_favorite=true`: Returns documents marked as favorite by the current user
         - `is_favorite=false`: Returns documents not marked as favorite by the current user
+        - `title=hello`: Returns documents which title contains the "hello" string
 
     Example Usage:
         - GET /api/v1.0/documents/?is_creator_me=true&is_favorite=true
-        - GET /api/v1.0/documents/?is_creator_me=false
+        - GET /api/v1.0/documents/?is_creator_me=false&title=hello
     """
 
     filter_backends = [filters.DjangoFilterBackend, drf_filters.OrderingFilter]