feat: remove need to define vault price structures

[okjintao]

Summary

Vaults are priced heuristically, we know the vault addresses and we know the deposit tokens. There is not an explicit need to define these pairings.

Requirements

• allow vaults prices to be automatically looked up assuming underlying token has prices

Example Removals

https://github.com/Badger-Finance/badger-api/pull/1547/files#diff-84ad9bcf8b383e631f1eaab853627c6d861c741d6945be9df4c743014d37ee7aR502-R515