Impose stable ordering on eduGAIN verify target

See ukf/ukf-meta#323 for details

mdx/int_edugain/verbs.xml

@@ -98,6 +98,21 @@
                     p:whitelistingEntities="false"
                     p:designatedEntities-ref="int_edugain_verify_blacklist"/>
 
+                <!--
+                    Sort the remaining entities by entity ID, so that any errors
+                    are reported in a stable order, even if some registrars
+                    have unstable output.
+
+                    Ideally this should be handled by an explicit ordering stage.
+                    Lacking one, we use the fact that we can use the ordering
+                    strategy ability of the EntitiesDescriptor assembler to
+                    order entities, and then disassemble again. Ordering is based
+                    on the ItemID populated into the item metadata.
+                -->
+                <ref bean="populateItemIds"/>
+                <ref bean="uk_assemble"/>
+                <ref bean="disassemble"/>
+
                 <ref bean="standardImportActions"/>
                 <ref bean="edugainPolicy"/>
                 <ref bean="warningAndErrorAnnouncer"/>