Restructure the Spec

[rlin1]

Goal: have one specification for SPs - that only includes aspects that are relevant for the SP, etc.

[rlin1]

Looked-up some Wallet APIs:

1. Google Wallet, see https://github.com/google-pay/wallet-samples
2. Apple Wallet, see https://developer.apple.com/documentation/passkit/wallet/
3. https://developer.samsung.com/wallet/api/overview.html
4. https://w3c-ccg.github.io/universal-wallet-interop-spec/
5. Old one for the web from 2015: https://github.com/playbanq/WebWalletAPI
6. https://documenter.getpostman.com/view/10058163/SWLk4RPL
7. https://github.com/dipanshuchaubey/wallet-app-api
8. https://docs.moralis.io/web3-data-api/evm/reference/get-transactions-by-wallet
9. https://developer.vivawallet.com/apis-for-payments/wallet-api/
   Note: there is no Wallet in OpenID4VC/VP - so a different trigger method is required.

Many are out there. The question is: is it even possible to harmonize them?
Open Wallet Foundation (https://openwallet.foundation/) tries to do that: "The OWF aims to set best practices for digital wallet technology through collaboration on standards-based OSS components that issuers, wallet providers and relying parties can use to bootstrap implementations that preserve user choice, security and privacy."