Migrate Guardian to Hedera DID SDK (meeco SDK)

[anvabr]

Problem description

Current Guardian tooling for working with DIDs originates from outside of Hedera ecosystem. Recent v1 version of Hedera DID spec is compatible with Guardian requirements. Reportedly https://github.com/Meeco/hedera-did-sdk-js (and soon https://github.com/hashgraph/did-sdk-js) library implements this specification, but it is not used by Guardian.

Requirements

Migrate Guardian to the new Hedera DID SDK js to ensure cross compatibility with the rest of Hedera ecosystem.

Definition of done

Guardian uses https://github.com/hashgraph/did-sdk-js.

Acceptance criteria

Guardian DIDs are compatible with the rest of the DIDs in Hedera ecosystem.