Integrate with external Guardian policies as data sources

[anvabr]

Problem description

Executing Guardian Policy workflow results in a production of artefacts, namely VCs and VPs, and ultimately minted tokens. Each of these artefacts is currently populated with relevant information as directed by the active Policy. Projects should have ability to enrich the data in these document with external information relevant to the specific project use-cases.

#1515 covers the basic data enrichment functionality, however there is also a need for creating functioning integrations to be existing out of the box, which users of Guardian could easily insert into their policies.

Requirements

• Support the use, from inside the policy, of VCs/VPs produced by other Guardian instances published in IPFS.
• Support manual entry of additional data (pdfs, text, VC docs, etc) into policies during execution.
• Support automatic retrieval of additional data via custom code block.
• TBD - Support integration with Agryo in the form of VCs
• Implement integration with these 3rd party data providers (may be similar to IPFS/Hedera integration), such as:
  • policy can easily add such 'integration' to their policy - potentially using the new policy modules functionality Linkable policy modules for constructing end-to-end Policy workflows #1657
  • the data can be defined as mandatory or optional (by the policy author)
  • data imported into Policy artefacts is stored and displayed in its native format, preserving 'mime type' and/or any other indication of the nature of the data as well as the identity/credentials of the source, time/date and other identifying information as appropriate

Definition of done

Out to the box Guardian supports integration via the identified methods, users can add this to the relevant stages of their policy workflow.

Acceptance criteria

It is possible to create a Policy which, upon execution, would produce artefacts (VCs/VPs) which would contain clearly marked (external) 3rd party data in its original format useful for clarifying, detailing or enhancing the information in the VC document.

[anvabr]

Consider prioritising

• other Guardian instances
• agrio.io
• google geo-location API

The record needs to contain:

• intent
• history