Implement AggregationSourceCollection

This is an intermediate step in setting up aggregation sources. A
future patch will add aggregation sources based on the existence of
satellite configs.  For now the collection will always return as 0
members.

Adds the AggregationSourceCollection schema which we previously
ignored.

Tested:
Service Validator passes

Signed-off-by: Carson Labrado <clabrado@google.com>
Change-Id: I65c9231289bf0a9b6392696d55bc3feb0023c694
diff --git a/redfish-core/include/redfish.hpp b/redfish-core/include/redfish.hpp
index 9d7bbaa..954dfc7 100644
--- a/redfish-core/include/redfish.hpp
+++ b/redfish-core/include/redfish.hpp
@@ -74,6 +74,7 @@
         requestAccountServiceRoutes(app);
 #ifdef BMCWEB_ENABLE_REDFISH_AGGREGATION
         requestAggregationServiceRoutes(app);
+        requestAggregationSourcesRoutes(app);
 #endif
         requestRoutesRoles(app);
         requestRoutesRoleCollection(app);