API-8577: Update sift-dotnet library with missed fields

[advornichenko-sift]

Purpose

https://sift.atlassian.net/browse/API-8577

Summary

• Added support for $ip field
• Added support for $user_email in $create_content event
• Added support for $reviewed_user_id in $create_content.review
• Added support for $verification_phone_number, $user_email in $update_content
• Added support for $reviewed_user_id in $update_content.review
• Updated sift-docs

Testing

• Unit tests
• Integration tests

Checklist

• The change was thoroughly tested manually
• The change was covered with unit tests
• The change was tested with real API calls (if applicable)
• Necessary changes were made in the integration tests (if applicable)
• New functionality is reflected in README

[npron-sift]

LGTM