Rego extension functions to transform DID:WEB to URL and vice-versa

Description

Two functions.

One converts from DID:WEB to URL and one from URL to DID:WEB

did_from_url("https://abc.com") -> did:web:abc.com
url_from_did("did:web:abc.com") -> https://abc.com

Acceptance Criteria

• Implementation
• Unit tests