haip deeplink drives implementations into undefined behavior on iOS

[breynders-cb]

The requirement of registering the haip:// custom scheme seems to force all haip-compatible wallets into undefined behavior on iOS as https://developer.apple.com/documentation/xcode/defining-a-custom-url-scheme-for-your-app states:

If multiple apps register the same scheme, the app the system targets is undefined. There’s no mechanism to change the app or to change the order apps appear in a Share sheet.

I realize there's no good solution to this regardless, but for a profile focused on interoperability it seems important. For the presentation of credentials the upcoming https://wicg.github.io/digital-credentials/#integration-with-credential-management-api will provide an alternative solution to this issue but even there, issuance is out-of-scope.

[jogu]

The first part I think should be covered by #121

The Digital Credentials group plans to cover issuance too, there's some discussions happening on WICG/digital-credentials#167 and we've some draft suggestions on how OID4VCI might look like over it on openid/OpenID4VCI#410