fix(AWSMobileClient): Fixing HostedUI not showed when using navigationController

[sebaland]

Issue #, if available:

• [Crash] SDK 2.36.0 AWSCognitoAuth launchUsing:uiViewController:completion: #5315

Description of changes:
Attempting to present the HostedUI with a navigationController always failed because no presentationAnchor is set.

I'm bringing back SFAuthenticationSession to solve this issue by reverting the changes made in #5223., as this workflow is meant to be a "legacy" one and not based on ASWebAuthenticationSession.

Check points:

• Added new tests to cover change, if needed
• All unit tests pass
• All integration tests pass
• Updated CHANGELOG.md
• Documentation update for the change if required
• PR title conforms to conventional commit style

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