Duckql

- **Fix**: Adding missing imports in `__init__.py` files inside of submodules
- **Change**: Moved `__version__` from `__init__.py` to `version.py`
- **Note**: Development status change to Alpha

- **Feature**: Introduced `functions.StringAgg`
- **Feature**: Introduced `structures.CastOperator`
- **Feature**: CLI for parsing files

- **Change**: Allow direct use of `structures.Comparision` in query conditions

- **Fix**: Allow aliases in `structures.Query`
- **Change**: Do not escape `%`

- **Feature**: Natural join support

- **Change**: Completed docs
- **Feature**: Recursive nested properties lookup in `Query` object