Implement AggregationSource

Adds an AggregationSource resource for each satellite config present on
dbus.

Adds the AggregationSource schema which we had previously ignored.

Tested:
Querying an AggregationSource returned the expected information.

curl localhost/redfish/v1/AggregationService/AggregationSources/5B247A
{
  "@odata.id": "/redfish/v1/AggregationService/AggregationSources/5B247A",
  "@odata.type": "#AggregationSource.v1_3_1.AggregationSource",
  "HostName": "http://122.111.11.1:80",
  "Id": "5B247A",
  "Name": "Aggregation source",
  "Password": null,
}

Service Validator passed.  The Service Validator also passed after
removing the satellite config from the system such that
/redfish/v1/AggregationService/AggregationSources returns an empty
Members array.

Signed-off-by: Carson Labrado <clabrado@google.com>
Change-Id: I88b5fbc15f27cddd330ec22a25427fd8b18cf766
diff --git a/redfish-core/include/schemas.hpp b/redfish-core/include/schemas.hpp
index c2cbb8b..8dd2d7b 100644
--- a/redfish-core/include/schemas.hpp
+++ b/redfish-core/include/schemas.hpp
@@ -18,6 +18,7 @@
         "AccountService",
         "ActionInfo",
         "AggregationService",
+        "AggregationSource",
         "AggregationSourceCollection",
         "Assembly",
         "AttributeRegistry",