Refine the metadata extraction behaviour

[galviset]

As discussed several times mostly about agents, there are some adaptations necessary when it comes to the process of extracting ontology metadata for the submission.

• for Agents, it has been reported that extracting them every time mess with the curation work done on portals, reintroducing bad Agents at every parse
• for Status, it has been discovered that if the ontology author puts a value that is not in our list (alpha, beta, production, retired), the ontology will automatically appear as retired on the UI and will not show up unless the filter is ticked on. The value is still extracted and visible, however.

Following our discussions with @imadbourouche and @jonquet today, we have several leads:

• refine the extracted field in the JSON to accept more than just true or false, like once for example
• the extraction function has been designed to be generic enough so it can be refined a bit. We could make so the extracted value is checked against our enforced value list, if there's one, and extract the value only if it's one of our enforced values.

[jonquet]

To be linked with other related issues.