Make extensions for `LoginFacade` and `Data` for external access

[itsmeichigo]

Part of https://github.com/woocommerce/woocommerce-ios/issues/10590

Description As part of the effort for https://github.com/woocommerce/woocommerce-ios/issues/10590, we want to support the login feature with custom UI from WCiOS while using the main logic from WordPressAuthenticator library. To support security key login, we need access to the new extensions of LoginFacade and Data.

Testing Please follow the testing step in https://github.com/woocommerce/woocommerce-ios/pull/11070.

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