Separate component items and component definitions CND

In order to provide a cleaner separation between component catalog items and component instances on JCR level, a new CND type 'hst:componentdefinition' has been introduced. From now on, that new type should be used as a definition for all future catalog items. New type supports new dynamic parameters feature and 'ctype' parameter.
 
[hst:componentdefinition]
-hst:componentdefinition(string)
-hst:componentclassname(string)
-hst:ctype(string) // a component type 'reference'  for frontend (SPA) development.
-hst:xtype(string)
-hst:iconpath(string)
-hst:label(string)
+*(hst:dynamicparameter)
 
[hst:containeritempackage] > nt:base, mix:referenceable orderable
+ * (hst:containeritemcomponent)
+ * (hst:componentdefinition)

On a code(implementation) level, the HstComponentConfigurationService still (also) represents 'hst:componentdefinition’ nodetype.

The more explicit code level (model) separation will be done separately later without any breaking changes for PaaS and SaaS.
Also note that the above additional hst:componentdefinition child nodes for a hst:containeritempackage retains the backwards compatibility for the 'legacy' usage of hst:containeritemcomponents in the catalog. The latter no longer will be used/support on SaaS.