CDM versioning

As a SKAMPI user, I want the CDM to support multiple schema versions so that I can configure and observe using JSON from different PIs without having to reconfigure and redeploy devices.

The CDM currently does not support multiple schema versions, which means that a SKAMPI deployment must be reconfigured and redeployed to match the specific version of the JSON that is to be used. Modify the CDM and/or provide the necessary support libraries so that applications using the CDM library can, at runtime, serialise/deserialise JSON defined using different CDM schema versions.

not actionable by an OSO team until the rest of SKAMPI can also handle versioning