Changes to Adapter Issue API URL

[rolsonquadras]

• Change path from connect/wallet to issue as issuance is the primary action here
• Change cred query param to scope to align with profile request
• Add txnID query param to correlate this request to callback redirect after the flow.

https://github.com/trustbloc/adapter/blob/main/docs/issuer/integration/issuer.md#redirect-the-user-to-adapter-api