Refactor @web5/crypto to replace Web Crypto CryptoKey with JWK

[frankhinek]

Feature Proposal Tasks:

• Propose API surface design prior to implementation. This can be done by creating a draft PR for a respective feature and providing prototypal code or proposing the design in the comments
• Approval Required from a minimum of 2 people

Implementation Tasks:

• Produce/update API reference documentation for any/all methods added to the public API surface. documenting private API methods is optional
• Produce/update relevant example usage
• Test coverage must be provided for all public API methods.
• Tests that consume shared test vectors must all be passing

[frankhinek]

Completed in PR #318