Local dev: Allow marking origins as "potentially trustworthy"

[Jubeki]

Currently it is not possible to run the webauthn flow from localhost (for local development purposes)
(This does not apply if you are using Valet with SSL-Certificates enabled)

What must be done for Webauthn support on localhost:

• SSL-Certificate or domain (localhost) is in secured_relying_parties
• Visit from http://localhost instead of http://127.0.0.1

This PR adds support for secured_relying_parties for the localhost option.

(This should probably never be active in production and only be added for local development purposes)

[claudiodekker]

Thanks! I'm gonna double-check this one in a bit. Just noting down some references for later:

• https://html.spec.whatwg.org/multipage/webappapis.html#secure-context
• https://w3c.github.io/webappsec-secure-contexts/#potentially-trustworthy-url
• https://developer.mozilla.org/en-US/docs/Web/Security/Secure_Contexts
• https://webauthn-doc.spomky-labs.com/symfony-bundle/advanced-behaviors/dealing-with-localhost#secured-context
• Unsecured context web-auth/webauthn-framework#126