Align the implementation of the DIDCommV2 protocol in cloud and edge agents (body property must be optional)

[yshyn-iohk]

UPDATE:

1. Follow the specification recommendation for thebodyproperty: to be fully compatible with DIDComm v2.0. It’s recommended always to have this attribute when sending a message, but allow the attribute not to exist when receiving.
2. Alight the internal properties of the body between the cloud agent and edge agents for each DIDCommV2 protocol and each message.

---

In the current implementation (Identus 2.14+), the body property of the messages is not optional.
It caused the inconsistencies and compatibility issues between the agents (cloud and edge)

An example of the issue is the body property in the issue-credential record.
In the cloud agent 1.40.0 the body was

{
  body: {
    comment: null,
    goad_code: null,
    more_available: null,
    replacement_id: null
  }
}

formats property was absent at all, but the edge agent TS tries to parse it as well

After refactoring the cloud-agent (circle json library was replaced with zio-json in this and this commits)

After cloud-agent 1.40.0, the body property became empty. No information is transmitted from the cloud to the edge agent:

{
  body: {}
}

At the same time, the body property is optional in the DIDCommV2 specification, and properties goal_code and replacement_id are optional as well:

body - OPTIONAL. The body attribute contains all the data and structure uniquely defined for the schema associated with the type attribute. If present, it MUST be a JSON object that conforms to [RFC 7159](https://datatracker.ietf.org/doc/html/rfc7159).

So, the cloud and edge agent must treat the body property according to the spec.

[yshyn-iohk]

Example of the message in the cloud-agent 1.40.0