Updated AuthButton style [SDK-1376]

[Widcket]

Changes

Updated AuthButton to match the new Lock.js style, that was in turn updated to prevent App Store rejections (due to the look of the SIWA button).

• Added a new property borderColor to AuthStyle
• Refactored the layout of AuthButton to remove the extra ImageView and use the one built in UIButton
• Centered the contents of AuthButton
• Replaced the Google icon for one without blue borders
• Title-cased the providers names
• Used "Sign in with ..." for both login and signup

Before

After

References

auth0/lock#1801

Testing

• This change adds unit test coverage
• This change has been tested on the latest version of the platform/language or why not

Checklist

• I have read the Auth0 general contribution guidelines
• All existing and new tests complete without errors
• All active GitHub checks have passed

[joshcanhelp]

Very clear, focused, and detailed-oriented PR here ... nice work! Main comment is about constants/enums for the network names and maybe the additive text as well, like "Sign in with" ... seems like a good candidate to define once and use multiple times.

Only other thing was a question about how this works ... this Lock form is loading within an application, correct? This is not displayed in a browser or anything?

Nothing blocking here 👍