Yang module retrieval

The "ietf-yang-library" module provides the information about the YANG modules and submodules defined in the SLX-OS. All YANG modules and submodules must be identified in the YANG module library.

This ietf-yang-library module is defined in the RFC7895 . The YANG tree diagram for ietf-yang-library.

+--ro modules-state
      +--ro module-set-id    string
      +--ro module* [name revision]
         +--ro name                   yang:yang-identifier
         +--ro revision               union
         +--ro schema?                inet:uri
         +--ro namespace              inet:uri
         +--ro feature*               yang:yang-identifier
         +--ro deviation* [name revision]
         |  +--ro name        yang:yang-identifier
         |  +--ro revision    union
         +--ro conformance-type       enumeration