a11y: add group role to blocks (#88620)

@@ -501,0 +504,4 @@
+
+    @property
+    def a11y_role(self):
+        # don't mark block as a group if it has no label

@@ -569,1 +580,3 @@
-            return htmltag('span', **attrs) + htmltext('</span>')
+            # add a tag even if there's no label to display as it's used as an anchor point
+            # for links to errors.
+            return htmltag('div', **attrs) + htmltext('</div>')