Get cm-handle state endpoint

Get cm-handle state endpoint

Added new get cm-handle state endpoint
Refactored RestOutputCmHandleState to CmHandleCompositeState
Created new RestOutputCmHandleCompositeState OpenApi object
^This is done so that we get '"state: {" at the start of JSON response
Refactored RestOutputCmHandleStateMapper to CmHandleStateMapper
Added more detailed composite state to get cmHandleDetails endpoint tests
Rebased code
Code rebased on top of 129658: Unable to change state from LOCKED to ADVISED | https://gerrit.onap.org/r/c/cps/+/129658 which fixes output error

Issue-ID: CPS-1019
Signed-off-by: mpriyank <priyank.maheshwari@est.tech>
Signed-off-by: lukegleeson <luke.gleeson@est.tech>
Change-Id: I361117c98c256a4aa578c13d21926bc6d7876a15