Implement the agents links as any other compel objects in the models

[jonquet]

This is about implementing agents also as links to stay consistent with what was done for other complex objects in the models.
E.g., https://data.agroportal.lirmm.fr/ontologies/AGRO/metrics

For the moment links contains:

And agents are directly included in the submission like this

So a call like this does not work :
https://data.agroportal.lirmm.fr/ontologies/AGRO/agents

If include=all is done on the /submission endpoint, then the data shall be grabed from the links and put in the outpiut explicilty.
This policy can also be generalized to any "links" that does not return too much data (basically that are about metadata) : metrics, reviews, notes, groups, categories, projects, analytics.
I would keep out the links that can possibly return too much data: submissions, properties, classes, roots, schemes, collections, instances, views

[jonquet]

Working on this, I suggest to change the capital A in the service to a lower case a:
https://data.agroportal.lirmm.fr/Agents/f8c13b10-7b3e-013c-7b07-5254006dce65
in the json returned by the submission
https://data.agroportal.lirmm.fr/ontologies/AGRO/latest_submission?display=endorsedBy&display_context=false

[syphax-bouazzouni]

done in #145