Support post-form submit option to prevent "intelligent" 3P cookie limits on Safari

[aeneasr]

Preflight checklist

• I could not find a solution in the existing issues, docs, nor discussions.
• I agree to follow this project's Code of Conduct.
• I have read and am following this repository's Contribution Guidelines.
• I have joined the Ory Community Slack.
• I am signed up to the Ory Security Patch Newsletter.

Ory Network Project

No response

Describe the bug

Doing AJAX submits with cookie setting is triggering Safari's intelligent 3P cookie detection due to the use of CNAME / CNAME "cloaking".

Reproducing the bug

Submit a login flow using a custom domain in Ory Network.

Relevant log output

Relevant configuration

Version

master

On which operating system are you observing this issue?

None

In which environment are you deploying?

None

Additional Context

Ideally, we would keep AJAX submit and solve this in kratos so that users don't have to sign in again after 7 days. If that is not possible, we should offer an feature flag in Ory Elements to do the form submit using traditional HTML submit, as that doesn't trigger 3P cookie detection as it's considered 1P. That's the way it currently works in the current ory elements.