Enhancement of Commerce Hub configurability

The Commerce Hub client can now be configured on the Spring application level using the config options as described on https://yidongnan.github.io/grpc-spring-boot-starter/en/client/configuration.html . The Commerce Hub client uses the property 'endpointName' of the 'commerceSettings' struct as configuration service name. If that service is not configured, the settings are inherited from the default service named 'GLOBAL'. If the property 'endpointName' is not set, the 'endpoint' property is used as both service name and address.

(CMS-13621)