Add support for publickey-credentials-create permission policy

[stephenmcgruer]

This PR adds support for publickey-credentials-create permission policy,
to support w3c/webauthn#1801

See also w3c/webauthn#1656

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Preview | Diff

[stephenmcgruer]

(I believe the build fails because the corresponding WebAuthn PR is not landed, so the dfn reference isn't there yet)

[stephenmcgruer]

cc @ve7jtb , who I believe wished to make sure that this was compatible with the previous L2 discussion on what create() in a cross-origin iframe would look like (particularly the permission policy name, I believe).

[nsatragno]

Looks good. Let's wait for the webauthn PR to be merged before merging this one.

[aaahlam621997]

يضيف هذا PR دعما لسياسة الأذونات ، لدعم w3c / webauthn # 1801publickey-credentials-create

انظر أيضا w3c/webauthn#1656

معاينة | فرق

[stephenmcgruer]

(Closing/opening just to kick the CI into re-running)

[stephenmcgruer]

So the CI is broken because the navigation re-write in HTML (whatwg/html#6315) un-exported the concept of a parent browsing context, and so the entire webappsec-credential-management spec will no longer build. Guidance from HTML folks is that the spec should be talking in terms of Navigables instead of browsing contexts, which I don't immediately understand very well 🤣

This is not related to this PR, so my suggestion is that we ignore the failing CI here and open an issue to track the failing build - wdyt @nsatragno ?

[nsatragno]

SGTM