feat: Add tests for SmartScraperGraph using sample text and configuration fixtures (@tejhande)

- Added pytest fixture to provide sample text from a file.
- Added pytest fixture to provide graph configuration.
- Implemented test_scraping_pipeline to test the execution of SmartScraperGraph.
- Added assertions to verify the result is not None and to check the expected structure of the result.

Contributed by @tejhande

Author: tejhande