Support provisioning v1 tokens signed by RSA when in issuer mode

[ripienaar]

Today we just pass all tokens to the issuer based provisioning method when in issuer mode. But we do support provisioning v1 protocol tokens to facilitate a gradual rollout to new provisioning tokens.

But since we pass all verification into issuer mode validation we also expect only ed25519 tokens, this is not the case for the gradual rollout problem as those would be older rsa signed tokens.

We should then use the new helper choria-io/tokens@a02dabb to determine the algo and only pass EdDSA method tokens into the issuer path, all the rest to old mode.