Implement Auth package into showcase app

[sekimondre]

Description

The goal of this integration is to be able to perform a full end-to-end authentication from the example apps.

The breakdown of this goal comprises of the following points:

• Update QR code URI with API prefix #454
• Display the Auth QR code from the Dapp
• Add a secondary scanner to the wallet to interact with Auth API*
• Create an Auth request prompt view in a similar fashion to Sign's proposal-approve flow
• Implement Dapp feedback for successful authentication

Notes

The current URI schema is indistinguishable to both Auth and Sign APIs, thus it needs, for now, a separate QR code generator and scanner to do the routing to the correct API. This is an UX issue to be discussed with the whole team.