T2730
Local implementation of getECPairFromWIF does not preserve types as required for tx builder to properly create a tx. This issue only occurs in prod (built) version, not in npm start version.
This will be a stacked diff where the library is pulled in and modified locally.
In part 1, we pull in bitcoincashjs-lib unchanged from https://github.com/Permissionless-Software-Foundation/bitcoincashjs-lib