Rust service

[encody]

Rewriting https://github.com/NEAR-Edu/stats.gallery-server/ in Rust, and making it a part of the main repo.

Benefits:

• Server speed, stability, efficiency
• Easier to write and add new badges
• Easier for new contributors to set up the project

The Rust server must have feature parity with the JS version of the server (sans instability, that is). Namely:

• Card generation (not started)
• Badges
• Background service that polls the indexer (or data lake) and updates local database
• All other queries (almost done iirc)