Azure: Support affinity for service running on localhost and reuse SPNEGO hadoop.auth cookie for authorization, SASKey and delegation token generation

Currently, WasbRemoteCallHelper can be configured to talk to comma separated list of URLs for authorization, SASKey generation and delegation token generation.
To improve the performance, if service runs on the local machine, give it first preference over the other configured list of URLs.
Currently, WasbRemoteCallHelper generates hadoop.auth cookie for every request by talking to the remote service, before making actual rest requests.
The proposal is to reuse the hadoop.auth cookie for subsequent requests from same WasbRemoteCallHelper object until its expiry time.