js lib for contracts

[taitruong]

There's ts-codegen for easily creating js libs. But it wont solve different versions of cw721.

Like in v16 there is Minter query, whereas in v18 it is Ownership and in upcoming v19 it is GetMinterOwnership.

New lib may have a version for constructor. In case of v16 then GetMinterOwnership call does an actual Minter call.

@shanev @JakeHartnell wdyt?

[JakeHartnell]

cw721 is probably a case that warrants making a dedicate npm library for to handle the different versions (including sg721 NFTs). Could also add some helper methods for fetching token_uri, etc.

ts-codegen output could be a good start for this.