Add CBOR to samples (or determine how to best document it)

[beriberikix]

Currently, only one sample shows how to use CBOR, despite CBOR support from 3 Device Services. This came up today when someone asked about implementing CBOR with LightDB Stream. We should decide if we want to add JSON AND CBOR examples, add CBOR as an alternative in each sample (if/else, )reference a snippet from the samples or something else. I don't have a recommendation at this time but multiple samples feel the least maintainable.

This also relates to #141.