Adhere to more modern BankID recommendations for opening in mobile device

[urizen-source]

PR fixes #533

We have been able to reproduce issue with Edge+Intune that are security restricted, this fixes the issue. It also emulates the behaviour we see on test.bankid.com and follows the BankID documentation. If I understand correctly, the No such orders is when it thinks it has created a request to BankID(using bankid://) but it has been blocked, so a cancel or other action without a real order gives the "no such order" message.

Stops use of bankid:// on mobile devices that are often security restricted. Instead uses the https://app.bankid.com,
Source: https://developers.bankid.com/getting-started/autostart
Quote: "To open the Mobile BankID app from a browser on a mobile device, you should use unversal links for iOS and app links for Android. "

Displays fallback button by default on mobile devices:
Source: https://developers.bankid.com/resources/ui-guide-mobile
Quote: "4. Promt user to open BankID. The BankID app should be opened automatically using autostart. However, in case this fails for some reason, the user should be asked to open the app manually."

[elinohlsson]

@urizen-source This is not really related to #508 as we discoursed earlier. It is related to launching the BankID security application, the latter part of your PR description. Could you add an issue which describes the problem and link it to this PR?

[urizen-source]

Issue created, link from this updated.

[okalangkenneth]

Some supporting evidence for this approach.

Looking into #543 (Edge on Android failing to open the BankID app) and #535 (Opera on Android failing to complete authentication after launch), both appear to be symptoms of the same underlying gap.... the current Chrome-only gate on App Links leaves other Chromium-based browsers without a working launch path.

This PR's approach of switching all mobile devices to https://app.bankid.com aligns with BankID's own documentation and would resolve both of those issues without needing per-browser special-casing going forward.

All checks are passing, and the changes look like they can be cleanly merged after a rebase. I can help with that or add test coverage if that would move this forward.