🔥(backend) remove api managing templates

A complete API was able to manage templates lifecycle, from the creation
to the deletion and managing accesses on them. This API is not used by
the frontend application, is not finished. A connected user can interact
with this API and lead to unwanted behavior in the interface. Refering
ot issue #1222 templates can maybe totaly remove in the future. While
it's here and used, we only keep list and retrive endpoints. The
template management can still be done in the admin interface.

src/backend/core/api/viewsets.py

@@ -1831,10 +1831,7 @@ class DocumentAccessViewSet(
 
 
 class TemplateViewSet(
-    drf.mixins.CreateModelMixin,
-    drf.mixins.DestroyModelMixin,
     drf.mixins.RetrieveModelMixin,
-    drf.mixins.UpdateModelMixin,
     viewsets.GenericViewSet,
 ):
     """Template ViewSet"""
@@ -1890,100 +1887,6 @@ class TemplateViewSet(
         serializer = self.get_serializer(queryset, many=True)
         return drf.response.Response(serializer.data)
 
-    @transaction.atomic
-    def perform_create(self, serializer):
-        """Set the current user as owner of the newly created object."""
-        obj = serializer.save()
-        models.TemplateAccess.objects.create(
-            template=obj,
-            user=self.request.user,
-            role=models.RoleChoices.OWNER,
-        )
-
-
-class TemplateAccessViewSet(
-    ResourceAccessViewsetMixin,
-    drf.mixins.CreateModelMixin,
-    drf.mixins.DestroyModelMixin,
-    drf.mixins.RetrieveModelMixin,
-    drf.mixins.UpdateModelMixin,
-    viewsets.GenericViewSet,
-):
-    """
-    API ViewSet for all interactions with template accesses.
-
-    GET /api/v1.0/templates/<template_id>/accesses/:<template_access_id>
-        Return list of all template accesses related to the logged-in user or one
-        template access if an id is provided.
-
-    POST /api/v1.0/templates/<template_id>/accesses/ with expected data:
-        - user: str
-        - role: str [administrator|editor|reader]
-        Return newly created template access
-
-    PUT /api/v1.0/templates/<template_id>/accesses/<template_access_id>/ with expected data:
-        - role: str [owner|admin|editor|reader]
-        Return updated template access
-
-    PATCH /api/v1.0/templates/<template_id>/accesses/<template_access_id>/ with expected data:
-        - role: str [owner|admin|editor|reader]
-        Return partially updated template access
-
-    DELETE /api/v1.0/templates/<template_id>/accesses/<template_access_id>/
-        Delete targeted template access
-    """
-
-    lookup_field = "pk"
-    permission_classes = [permissions.ResourceAccessPermission]
-    throttle_scope = "template_access"
-    queryset = models.TemplateAccess.objects.select_related("user").all()
-    resource_field_name = "template"
-    serializer_class = serializers.TemplateAccessSerializer
-
-    @cached_property
-    def template(self):
-        """Get related template from resource ID in url."""
-        try:
-            return models.Template.objects.get(pk=self.kwargs["resource_id"])
-        except models.Template.DoesNotExist as excpt:
-            raise drf.exceptions.NotFound() from excpt
-
-    def list(self, request, *args, **kwargs):
-        """Restrict templates returned by the list endpoint"""
-        user = self.request.user
-        teams = user.teams
-        queryset = self.filter_queryset(self.get_queryset())
-
-        # Limit to resource access instances related to a resource THAT also has
-        # a resource access instance for the logged-in user (we don't want to list
-        # only the resource access instances pointing to the logged-in user)
-        queryset = queryset.filter(
-            db.Q(template__accesses__user=user)
-            | db.Q(template__accesses__team__in=teams),
-        ).distinct()
-
-        serializer = self.get_serializer(queryset, many=True)
-        return drf.response.Response(serializer.data)
-
-    def perform_create(self, serializer):
-        """
-        Actually create the new template access:
-        - Ensures the `template_id` is explicitly set from the URL.
-        - If the assigned role is `OWNER`, checks that the requesting user is an owner
-          of the document. This is the only permission check deferred until this step;
-          all other access checks are handled earlier in the permission lifecycle.
-        """
-        role = serializer.validated_data.get("role")
-        if (
-            role == choices.RoleChoices.OWNER
-            and self.template.get_role(self.request.user) != choices.RoleChoices.OWNER
-        ):
-            raise drf.exceptions.PermissionDenied(
-                "Only owners of a template can assign other users as owners."
-            )
-
-        serializer.save(template_id=self.kwargs["resource_id"])
-
 
 class InvitationViewset(
     drf.mixins.CreateModelMixin,