feat: Add Lighthouse PeerDAS Dashboard (#736)

Grafana dashboard for monitoring Lighthouse PeerDAS metrics.

<img width="883" alt="Screenshot 2024-08-10 at 19 04 13"
src="https://github.com/user-attachments/assets/53a1f05f-ad5a-49ad-8879-edaa816f8072">

Author: KatyaRyazantseva