Group
* Decouple element from `Group` * Change `SUITE_ID` to `u16` and rework `get_context_string()` * Rework scalar de-serialization * Rename `Group` methods - `random_nonzero_scalar` -> `random_scalar` - `scalar_as_bytes` -> `serialize_scalar` - `scalar_invert` -> `invert_scalar` * Rework element de-serialization * Rename and remove `Group` methods `to_arr` -> `serialize_elem` `base_point` -> `base_elem` `is_identity` -> removed `identity` -> `identity_elem` `zero_scalar` -> hidden behind `cfg(test)` * Sort `Group` methods * Rework `expand_message_xmd` and remove utility * Improve P256 `hash_to_scalar`
* Introduce `Result` shorthand, re-export and rename `InternalError` * Re-export some public API relevant types * Move `deserialize` * Remove branch in `i2osp` * Make `serialize` and `serialize_owned` methods * Update p256