Moving types and core functionality from Gauntlet to SDK

[kylesmartin]

Group types not under commands that depend on them, but as general types somewhere like contracts/ocr2/types.ts.

Long term we'll need to think about the overall structure of our TS toolchain (SDK + Gautlet). One of the suggestions would be to move types and core functionality to our TS SDK (@chainlink/solana-sdk) and then build Gauntlet on top of it.

cc @RodrigoAD

Originally posted by @krebernisak in #300 (comment)