Enable statistics for Virtual private endpoint gateways

Currently the only visible metrics that is available for VPE gateways are GIGABYTE_TRANSMITTED and INSTANCE_HOUR present in the billing usage overview. As the VPE gateways are becoming common requirement for many services present on IBM Cloud it would be beneficial to have a possibility to retrieve those metrics via VPE gateway API. For example Load Balancers already provide loadbalancer-statistics  command on ibmcloud cli which enables users or administrators to preview traffic on load balancers. 

This idea is to request an extension of VPE gateway API which would provide the possibility to query metrics like connections count, data transmitted, active connections or health status.