Native Light Entity Support

Adds native Light entity support for the Blynk integration.

✨ New

• New "Light" pin type → creates light.* entities instead of number.*
• Brightness control (HA 0–255 ↔ Blynk 0–100)
• Works with MQTT and HTTP API modes

🙏 Credits

Thanks to @devanshtangri for the contribution! (#4)
#4