Annotation retrieval: fix modified-since condition to include removal

Some front-end services like the Neuron Name Service keep track when
they last updated (meta-)annotations and on a refresh() they ask the
back-end to only return results when the annotations changed since the
last update. The back-end SQL implementation of this wasn't working
correctly: it didn't take into account the removal of annotations and
meta-annotations. This is fixed now by also looking at changes in the
past using the history tables. With this in place, the modified-since
check works as expected and e.g. the Neuron Name Service in the
front-end will refresh names correctly when an annotation is removed.

Fixes #2237

django/applications/catmaid/control/skeleton.py

@@ -3599,8 +3599,11 @@ def get_annotation_info(project_id, skeleton_ids, with_annotation_names, metaann
 
     if cond_skeleton_ids:
         if metaannotations:
+            # Look at current data and history to see if there has been a recent
+            # change. We need to look at the history to see annotation removals
+            # too.
             meta_join = """
-            JOIN class_instance_class_instance cici_meta_ann
+            JOIN class_instance_class_instance__with_history cici_meta_ann
                 ON cici_meta_ann.class_instance_a = cici_ann.class_instance_b
             """
             meta_where = """
@@ -3611,12 +3614,14 @@ def get_annotation_info(project_id, skeleton_ids, with_annotation_names, metaann
             meta_join = ''
             meta_where = ''
 
+        # Look at current data and history to see if there has been a recent
+        # change. We need to look at the history to see annotation removals too.
         extra_skeletons = f"""
             UNION ALL
             SELECT cici.class_instance_a, cici.class_instance_b
             FROM class_instance_class_instance cici
 
-            JOIN class_instance_class_instance cici_ann
+            JOIN class_instance_class_instance__with_history cici_ann
                 ON cici_ann.class_instance_a = cici.class_instance_b
 
             {meta_join}