Data Model extensions

[wagmarcel]

• Add example for iri and strip down non-used fields
• Add e-class example

[wagmarcel]

Proposal created#
https://github.com/wagmarcel/json-schema-ngsild
Now contains examples for eclass and how to wrap it into JSON-LD
Next steps: Clean-up the context to put it on official IFF website
https://developement.industry-fusion.com/json-ld/vtest/core-context.jsonld

[wagmarcel]

Change of proposal: We are using github pages to manage the context (and other aspect)
Github pages can be used for github names individually or for organizations.
e.g. github names it would look like https://wagmarcel.github.io/json-schema-ngsild/schema-ngsild-eclass/context.jsonld and for IndustryFusion organization it could look like https://IndustryFusion.github.io/contexts/v0.1/context.jsonld => @abhijith-hr

@wagmarcel please update the ngsi-ld context to version 1.7 => https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context-v1.7.jsonld