feat: add Civil 3D test suite and update pytest configuration
- Introduced a new test suite for Civil 3D, including fixtures and tests for active document, database, and various Civil 3D-specific APIs.
- Updated `pyproject.toml` to configure pytest for Civil 3D, changing the test paths and host details.
- Added multiple test files covering geometry, document properties, and image export functionalities.
- Ensured compatibility with the existing pytest framework while expanding support for Civil 3D testing.