Refactoring Yaml layout for Cisco.
          Move CISCO CDP yaml to CISCO folder and combine it with ciscoSystem.
          Remove CDP Globle Service Element Type and its attributes be part of ciscoSystem Service Element Type.

    Implement Yaml parser for Service element instance signature and signature discriminator.
    Create service element instance signature for CISCO system based on entity chassis series  number and model name.
    Create service element unique signature discriminator for CISCO system.