Data Product should include necessary params and values to retrieve data from source

[kyyberi]

Describe the bug

Connector is not able to read configurations for data products from data product spec file.

Expected behavior

Data Product payload can have three streams:

• Current values
• History values
• Prediction values

Each of the call requires somewhat different params and values for retrieving the data from source. Data Product should contain the needed param values. The values are written to database when the data product is created. Below is just a rough sketch of the need.

[ralucaoanapopa]

not updated yet; checked

• https://dataproduct.oftrust.net/schemas/dps-document-schema
• https://dataproduct.oftrust.net/schemas/dps-document-schema/connector

[IrinaZayats]

We updated payload options with three possible configurations for current, prediction, and historical values. Currently, payload definitions are part of the Ontology, and adding them explicitly to the Data product spec will create ambiguity. So we added them as links to Ontology with specification of exact supported versions.

We added them on the data product and then connectors do not duplicate exact payload definitions links but specify which type of streams they support and witch definition versions.

If this implementation works, we will add also respective fields, now it is specified only on the example level. Please find the example here: https://dataproduct.oftrust.net/schemas/dps-document-schema