[FIX] base: add cumulated to rng graph file

This commit adds cumulated optional attribute to the graph view rng
definition.

`cumulated` graph attribute is used, defined and tested in PR #97394.

closes odoo/odoo#111880

X-original-commit: 5be91c78c687cc2ac8fd3f9a94e4e8ef2b951efa
Signed-off-by: Dardenne Florent (dafl) <dafl@odoo.com>

odoo/addons/base/rng/graph_view.rng

@@ -24,6 +24,7 @@
             <rng:optional><rng:attribute name="disable_linking"/></rng:optional>
             <rng:optional><rng:attribute name="sample"/></rng:optional>
             <rng:optional><rng:attribute name="banner_route"/></rng:optional>
+            <rng:optional><rng:attribute name="cumulated"/></rng:optional>
             <rng:zeroOrMore>
                 <rng:ref name="field"/>
             </rng:zeroOrMore>

odoo/addons/base/tests/test_views.py

@@ -3286,6 +3286,9 @@ class TestViews(ViewCase):
             'A <graph> can only contains <field> nodes, found a <label>'
         )
 
+    def test_graph_attributes(self):
+        self.assertValid('<graph string="Graph" cumulated="1" ><field name="model" type="row"/><field name="inherit_id" type="measure"/></graph>')
+
     def test_view_ref(self):
         view = self.assertValid(
             """