[TECHDEBT] Align CPS NCMP REST API Specification

- Updated ncmp.yml to align implementation with specification
- Added new Exception classes to differentiate between server NCMP
  issues and client based NCMP issues
- Added 500 error to specification
- To be merged after https://gerrit.onap.org/r/c/cps/+/126848
- Added excpetion handlers for SerNcmpException & DmiRequestException

Issue-ID: CPS-823
Signed-off-by: JosephKeenan <joseph.keenan@est.tech>
Change-Id: If1c9c6c29c6ea2daa07753d7f766ef15c1ba4ca0
12 files changed