feat: function package #33

The crypto api exposes a set of primitives. In such a manner the wallet just wraps around it for the sake of convenience and architecture (e.g.: the user/owner wallet is a single instance on msb and peer). As a goal, I would keep that wallet as dump as possible and concentrate the logic on the crypto-api. The wallet would just wrap and orchestrate (in this context proxy validation, proxy sign/verify and persist). Some missing features to accomplish that are:

• sanitizeDerivationPath
• validateHrp
• decodeBech32mSafe