Send device key for OTP challenge to prevent a new one from being cre…

[bartdl]

…ated. Handle resulting SRP Auth Action in challenge response.

• PR title and description conform to Pull Request guidelines.

Issue #, if available:

Description of changes:
Added key device if it is available for MFA challenge requests and added handling for the resulting SRP Auth action that is returned from the API after the change to send device key.

How did you test these changes?
Tested using email MFA in our application and a locally published version of the sdk.

Documentation update required?

• No
• Yes (Please include a PR link for the documentation update)

General Checklist

• Added Unit Tests
• Added Integration Tests
• Security oriented best practices and standards are followed (e.g. using input sanitization, principle of least privilege, etc)
• Ensure commit message has the appropriate scope (e.g fix(storage): message, feat(auth): message, chore(all): message)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.