Allow different Codecs for the same contentType

[danielpeintner]

At the moment, it is possible to "register" one Codec per contentType via ContentSerdes.

e.g., ContentSerdes.get().addCodec(new MyCodec("application/myType"))

There are situations where this is not enough. For example, one might want to register a generic codec for application/octet-stream and yet another for the same application/octet-stream which is used for binding-opcua only.

We should extend the API in a way to allow for that use-case.

[relu91]

Just as a note, this is a practical solution for exotic content-types or "not-yet-registered" content-types or forced data-mapping, as in theory, one content-type should not allow any ambiguity.

[danielpeintner]

Mhh, in the case of rather generic contentTypes likes application/octet-stream it would be still good to be able to specify a different codec based on the binding...