Support for Metadata Definitions Catalog API

API calls and shell commands added in this patch:
- CRUD for metadefs namespaces;
- CRUD for metadefs objects;
- CRUD for metadefs properites;
- CRD for metadefs resource types and resource type associations.

Change-Id: I6d15f749038e8fd24fc651f0b314df5be7c673ef
Implements: blueprint metadata-schema-catalog-support
Co-Authored-By: Facundo Maldonado <facundo.n.maldonado@intel.com>
Co-Authored-By: Michal Dulko <michal.dulko@intel.com>
Co-Authored-By: Lakshmi N Sampath <lakshmi.sampath@hp.com>
Co-Authored-By: Pawel Koniszewski <pawel.koniszewski@intel.com>