Reserve one of 4 nodeId digits for zoneId for Multi DC

[pradeepdalvi]

At present nodeId ensures uniqueness of ID generated within node by collision checker and across nodes using nodeId, however it may lead to collisions in multi DC setup.

• One workaround is to having separate prefixes in each DCs, which would push all services to modify their Id Generation logic and/or move them to config.
• Another way (which is implemented here) could be, reserving one of 4 digits of nodeId for zoneId or fameId. This creates a room for 10 zones and also leaves adequate room for number of instances i.e. 999.

Second approach has been implemented here. This approach also makes service registry & discovery DC/zone/partition aware without change in length of id generated.