Equip wallet-vc with a secure store solution

[IngridPuppet]

ADORSYS-GIS/wallet-vc-libs#51 (comment)

Discussing with @stephane-segning , we came up with a practicable solution that also suport off line use cases.

• The application will request a 6 digit number from the user to start.
• The appliation will backup those 6 digit number into a key server.
• The key server will support passkey for authentication.
• If the device does not support passkeys, the key server will require OTP.

I think this shall solve most of our problems.

Tasks:

• Onboard user to set up a PIN for the secure store #15

[nitch2019]

@forkimenjeckayang please add a comment to the dependencies for this ticket

[forkimenjeckayang]

The completion of this task is dependent on :

• This project from the mediator team: https://github.com/ADORSYS-GIS/Secret-server-rs
  After which , we have to revisit our onbaoriding logic for the wallet to integrate with the key server

[francis-pouatcha]

Secret server is obsolete. Now depends on: adorsys/didcomm-mediator-rs#328

As soon as WebAuthN Library is available with PRF, integrate it in this application.