ALMAS14 — No standard DDS key specification

The DDS-Xtypes specification now provides a standard way of specifying keys. This specification should use that mechanism

Add @key Annotation

In the DDS/IDL PSM use the @key Annotation as defined in IDL 4.2 (for XTYPES) - see https://www.omg.org/spec/IDL/4.2/PDF 8.3.2.1. for all the key values.
Note that the keys are currently defined in the keylist defined by pragma.
For backwards compatibility use a processor directive variable to switch between the styles of definition.