Sift

- Updated implementation to use Basic Authentication instead of passing `API_KEY` as a request parameter for the following calls:
- `client.score()`
- `client.get_user_score()`
- `client.rescore_user()`
- `client.unlabel()`

- Added support for a `warnings` value in the `fields` query parameter

- Support for Python 3.12

- Score percentiles for Score API

- Support for Verification API

- Added support for score_percentiles