DEV: Refactor webauthn to support passkeys (1/3) (#23586)

This is part 1 of 3, split up of PR #23529. This PR refactors the
webauthn code to support passkey authentication/registration.

Passkeys aren't used yet, that is coming in PRs 2 and 3.

Co-authored-by: Alan Guo Xiang Tan <gxtan1990@gmail.com>

spec/system/user_page/user_preferences_security_spec.rb

@@ -14,6 +14,9 @@ describe "User preferences for Security", type: :system do
 
   describe "Security keys" do
     it "adds a 2F security key and logs in with it" do
+      # system specs run on their own host + port
+      DiscourseWebauthn.stubs(:origin).returns(current_host + ":" + Capybara.server_port.to_s)
+
       # simulate browser credential authorization
       options = ::Selenium::WebDriver::VirtualAuthenticatorOptions.new
       page.driver.browser.add_virtual_authenticator(options)