+ Merge Balazs' fixes in _3gpp-nr-nrm-cpciconfigurationfunction.yang to this...

+ Merge Balazs' fixes in _3gpp-nr-nrm-cpciconfigurationfunction.yang to this branch (i.e. merge commit '411ff4c3' into 28.541_Rel17_CR_JanLindblad_Fix_YANG_Mapping_problems)
+ Introduce top level instance lists for all classes under ManagedElement based on Balazs' pattern
+ Move some type definitions to _3gpp-5g-common-yang-types.yang
+ Clean out all pyang --3gpp errors in all touched modules.
+ Respect multiplicity 1 as stated in stage 2 for a number of Energy Saving lists
+ Change synthetic index name from id to idx inside classes
+ Copy full description text from stage 2 for a number of elements that had abbreviated descriptions
+ Remove container attributes from lists inside classes
+ Added reciprocal must statement for startTime and endTime
+ Added missing revision statements in main modules _3gpp-ns-nrm-networkslice.yang and _3gpp-ns-nrm-networkslicesubnet.yang