Dyntastic

- Make Dyntastic.batch_get work with keys that are aliases on the model fields.
- Improve error messages when validating keys passed to `get`, `safe_get` or `batch_get`
- Minor fixes to `batch_get` type hints

- Add support for `__table_region__` and `__table_host__` to be lazy callables
- Default `__table_region__` and `__table_host__` to `DYNTASTIC_REGION` and
`DYNTASTIC_HOST` environment variables if not otherwise defined

- Fix import error when using `pydantic>=2.5`

- Add support for python3.12

- Add support for pydantic v2

- Support KEYS_ONLY and INCLUDE DynamoDB indexes