Update CDC pipeline demos with serverless compute and CDF best practices

- Migrate to serverless compute with trigger(availableNow=True)
- Add continuous CDC data generators for realistic simulation
- Implement CDF vs non-CDF processing volume demonstrations
- Restructure demos with 8 numbered steps for clarity
- Add performance optimizations (delta properties, auto loader config)
- Fix schema evolution and column name issues
- Remove deprecated Spark configurations
- Add real-time monitoring and progress tracking

Author: mkhelghati-db