Add Support for DIDComm V2

[Custard7]

Feature Request

DIDComm V2 Support

Describe the Feature

Add a plugin for LearnCard SDK to support sending / receiving VCs using DIDComm v2 protocol.

Why does the community need this feature?

There are three major open-standards protocols reaching broad community adoption for sending Verifiable Credentials: VC-API, OIDC, and DIDComm v2. LearnCard should support all three protocols for maximum interop. Additionally, DIDComm v2 is a powerful protocol for asynchronous delivery of credentials, including to devices that may be offline for periods of time (i.e. a mobile device), agnostic to transport mechanisms (http, snail mail, etc.).

Additional context

JFF Plugfest II is supporting DIDComm v2 as a protocol for interop demonstration - would be great to be a part of this community!