Enhance DownloadSponsors with Robust Error Handling, Retry Mechanisms, and Data Validation

[DiegoPisa2003]

This PR improves the DownloadSponsors class by adding error handling, retry mechanisms, data validation, and duplicate detection capabilities. These enhancements make the sponsor downloading process more reliable, maintainable, and debuggable.

Changes made

Implemented a comprehensive enhancement strategy with the following key improvements:

1. Custom Exception Classes & Constants

• DownloadError for download-related failures
• ValidationError for data validation failures
• Configurable constants: MAX_RETRIES, RETRY_DELAY, NETWORK_TIMEOUT

2. Intelligent Retry Mechanism

• Generic with_retry method with exponential backoff
• Configurable retry attempts

3. Comprehensive Data Validation

• Structure validation ensuring data follows expected schema
• Field validation with defaults for missing data
• Automatic slug generation using Rails' parameterize method, in case the AI did not bring it
• URL normalization and validation

4. Duplicate Detection & Merging
5. Enhanced File Operations
6. Improved Error Handling & Logging

• Comprehensive error catching throughout the pipeline
• Detailed error messages with backtraces