Improve error message for email/password sign-in on OAuth accounts

[ashishyk018-byte]

Fixes #1313

Improves the error message shown when Email/Password sign-in is attempted
for accounts originally created via OAuth, without relying on deprecated
auth APIs.

Manually verified the updated error handling logic.

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[ashishyk018-byte]

Thanks! Happy to make any changes if needed 🙂

[russellwheatley]

Hi @ashishyk018-byte - Thank you for the PR. We haven't made a decision on the best approach to this particular issue at this moment in time, but I'll let you know when a decision has been made 🙏

[ashishyk018-byte]

Thanks for the update! 👍
Happy to adjust the approach or make changes once a direction is decided.

[ashishyk018-byte]

The relevant change for this PR is the commit Clear form validation errors when input is corrected

[russellwheatley]

@ashishyk018-byte - I'd remove all other code changes (except in this PR) as they have been resolved in a different PR. Also - add something similar to angular as well, this is only for react at the moment.

Finally - add a test that demonstrates that this error message is produced. Thanks!

[ashishyk018-byte]

Thanks for the feedback!
I'll remove the unrelated code changes and keep only the relevant updates in this PR.
I'll also implement similar changes for Angular and add a test case to demonstrate the error message as suggested.
Will update the PR shortly.