Fix influxdb3 sink retention policy handling and timestamps len

[rodas96]

Summary

Adds graceful handling of InfluxDB retention policy violations (HTTP 422 errors) to prevent pipeline crashes when writing data outside the configured retention period. And fixes timestamps len

Changes

• ✅ Added raise_on_retention_violation parameter (default: False) for optional strict mode
• ✅ HTTP 422 errors with "retention policy" message are logged as warnings and skipped by default
• ✅ Kafka offsets are committed, preventing infinite retry loops
• ✅ Other 422 errors (schema conflicts, etc.) still raise exceptions
• ✅ Added comprehensive test coverage for both default and strict modes
• ✅ Updated documentation
• ✅ Fixed timestamp lens