[BSIP40] Add external serializations

See https://github.com/bitshares/bitshares-core/pull/
2093#discussion_r399386266

Author: nathanielhourt

libraries/protocol/custom_authority.cpp

@@ -98,3 +98,10 @@ void custom_authority_delete_operation::validate()const {
 }
 
 } } // graphene::protocol
+
+GRAPHENE_IMPLEMENT_EXTERNAL_SERIALIZATION(graphene::protocol::custom_authority_create_operation::fee_parameters_type)
+GRAPHENE_IMPLEMENT_EXTERNAL_SERIALIZATION(graphene::protocol::custom_authority_update_operation::fee_parameters_type)
+GRAPHENE_IMPLEMENT_EXTERNAL_SERIALIZATION(graphene::protocol::custom_authority_delete_operation::fee_parameters_type)
+GRAPHENE_IMPLEMENT_EXTERNAL_SERIALIZATION(graphene::protocol::custom_authority_create_operation)
+GRAPHENE_IMPLEMENT_EXTERNAL_SERIALIZATION(graphene::protocol::custom_authority_update_operation)
+GRAPHENE_IMPLEMENT_EXTERNAL_SERIALIZATION(graphene::protocol::custom_authority_delete_operation)

libraries/protocol/include/graphene/protocol/custom_authority.hpp

@@ -134,3 +134,10 @@ FC_REFLECT(graphene::protocol::custom_authority_update_operation,
            (fee)(account)(authority_to_update)(new_enabled)(new_valid_from)
            (new_valid_to)(new_auth)(restrictions_to_remove)(restrictions_to_add)(extensions))
 FC_REFLECT(graphene::protocol::custom_authority_delete_operation, (fee)(account)(authority_to_delete)(extensions))
+
+GRAPHENE_DECLARE_EXTERNAL_SERIALIZATION(graphene::protocol::custom_authority_create_operation::fee_parameters_type)
+GRAPHENE_DECLARE_EXTERNAL_SERIALIZATION(graphene::protocol::custom_authority_update_operation::fee_parameters_type)
+GRAPHENE_DECLARE_EXTERNAL_SERIALIZATION(graphene::protocol::custom_authority_delete_operation::fee_parameters_type)
+GRAPHENE_DECLARE_EXTERNAL_SERIALIZATION(graphene::protocol::custom_authority_create_operation)
+GRAPHENE_DECLARE_EXTERNAL_SERIALIZATION(graphene::protocol::custom_authority_update_operation)
+GRAPHENE_DECLARE_EXTERNAL_SERIALIZATION(graphene::protocol::custom_authority_delete_operation)