Allow any sub-items to be moved from a folder

Since you can now see them when searching you should also be able to
select and move them. Which means that they needed to be included in
the `Form`’s list of possible choices of things to move.

app/models/template_list.py

@@ -44,6 +44,10 @@ class TemplateList():
                 ancestors=ancestors,
             )
 
+    @property
+    def as_id_and_name(self):
+        return [(item.id, item.name) for item in self]
+
     @property
     def templates_to_show(self):
         return any(self)