Use traffic light colors as background for status payloads

[gustavovalverde]

We're testing the application with status payloads https://github.com/Path-Check/paper-cred/blob/main/payloads/status.2.md

As this payload is a more straightforward way to verify the vaccination status, it would be nice to have traffic light colors to identify each status:

• 0: Red 🔴
• 1: Yellow 🟡
• 2: Green 🟢

As this improves the UX, it would allow a faster verification process.

[vitorpamplona]

Great idea! I just don't know how many Red backgrounds would be out there since status=0 are generally not being issued at all.