Export more information in RAPI group queries

Sadly we don't have a way to test that, for example, all
(G|N|I)Q_CONFIG fields are exported in RAPI, so for now we don't test
this; but we should, in the future.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

lib/rapi/rlib2.py

@@ -96,6 +96,11 @@ G_FIELDS = [
   "node_cnt",
   "node_list",
   "ipolicy",
+  "custom_ipolicy",
+  "diskparams",
+  "custom_diskparams",
+  "ndparams",
+  "custom_ndparams",
   ] + _COMMON_FIELDS
 
 J_FIELDS_BULK = [