Creates a new `EditPredictionProvider` for zeta2, that requests completions from a new cloud endpoint including context from the new `edit_prediction_context` crate. This is not ready for use, but it allows us to iterate. Release Notes: - N/A --------- Co-authored-by: Michael Sloan <michael@zed.dev> Co-authored-by: Bennet <bennet@zed.dev> Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>