Add support for BCH

[ltardivo]

Currently BCH is not supported by the Bitcion Computer. Similar integration has been done for Pepecoin [#227] and Dogecoin [#156][#322].

This issue requires to implement the compatibility with the following tasks:

Core

• Select or create a BitcoinCash docker image. We can get started with this linux/amd64 image, but a multiplatform image would be preferred. This is the repository of the project.
• Modify @bitcoincomputer/nakamotojs library to include Bitcoin Cash network configuration.
• Create a file /chain-setup/BCH/regtest/.env.example and /chain-setup/BCH/regtest/bitcoin.conf.example file, use pepe as inspiration

Apps

• Include BitcoinCash as options in the wallet component
• Include BitcoinCash example environment variables for react apps