feat(rtn-passkeys): modify existing implementation - 2

[jjarvisp]

Description of changes

The purpose of this PR is modify the existing auth and react-native packages to support the new rtn-passkeys package.

• Minor refactoring of existing client/utils/passkey folder and file structure.
• Adds internal util for detecting native errors.
• Modifies error handlers to support native error structure.
• Adds unit tests for native code paths.
• Replace existing unsupported APIs with actual implementation.

Issue #, if available

Description of how you validated changes

Checklist

• [x] PR description included
• [x] yarn test passes
• [x] Unit Tests are changed or added
• [ ] Relevant documentation is changed or added (and PR referenced)

Checklist for repo maintainers

• [ ] Verify E2E tests for existing workflows are working as expected or add E2E tests for newly added workflows
• [ ] New source file paths included in this PR have been added to CODEOWNERS, if appropriate

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