DeFi Llama TVL adapter

[2qx]

Write adapter to capture TVL for v1 contracts.

see: DefiLlama/DefiLlama-Adapters#5495

[2qx]

This has been wired up in the cat app, but commiting stats to a json isn't done yet.

It needs to work with incremental updates, reading old DB and writing it back to the repo.