Add support for requesting account creation when sending auth magic link

[hichamboushaba]

⚠️ Please don't merge until the Podfile is updated with a trunk version of WordPressKit.

Part of: woocommerce/woocommerce-ios#14419

This PR adds support for requesting the creation of the account when using WordPressComAccountService/requestAuthenticationLink, this allows using the same WPCom endpoint for sending magic link to both existing and new accounts.

Testing

Check woocommerce/woocommerce-ios#14431

---

• I have considered if this change warrants release notes and have added them to the appropriate section in the CHANGELOG.md if necessary.

[hafizrahman]

Code looks good as it's simply getting the latest change from WordPressKit and using the new function from there.

[mokagio]

@hichamboushaba @hafizrahman

⚠️ Please don't merge until the Podfile is updated with a trunk version of WordPressKit.

I took over this PR fix the WordPressKit dependency wiring. I've enabled auto merge and will proceed to update WooCommerce to point to these changes once they land.