Add tutorial for content filtering subscription (#1270)

This PR introduces a comprehensive tutorial for content filtering subscription functionality in rclnodejs. Content filtering allows subscribers to filter messages at the DDS middleware level using SQL-like expressions, reducing network traffic and computational overhead.

### Key Changes
- Added complete tutorial documentation for content filtering subscription feature
- Provided practical examples covering temperature monitoring, robot motion filtering, and multi-sensor data processing
- Included compatibility checks, troubleshooting guidance, and best practices

Fix: #1269

Author: minggangw