[ATSv2 Security] Changes for authentication for CollectorNodemanagerProtocol

Communication between Collector and NM is via RPC.
We would do kerberos based authentication for communication between these 2 components, as of now. Added SecurityInfo implementation for it.
We can think of adding token based access once collector starts outside of NM.

Also creation of timeline client within NMTimelinePublisher would be done using NM login UGI.