Token Verifier Improvements

[javiertoledo]

Rework #1111 to adapt the changes to the new TokenVerifier interface and class structures.

• Replaces jsonwebtoken and jwks-rsa dependencies with jose because jose has zero dependencies.
• Adds a new EncryptedTokenVerifier token verifier implementation which can be used to decrypt JWE tokens. This can be useful when using libraries like NextAuth.js.
• Given the higher level of abstraction of jose, the JWT utility methods are no longer needed and have been removed.

Pending before closing this PR:

• [ ] Fix tests and verify they're all passing
• [ ] Update the documentation with the affected changes (removal of the JWT utilities and creation of the new EncryptedTokenVerifier class).