Add Private Testnet bundles generator

[nkuba]

We need to generate a bundles for the parties that are joining our Private Testnet.

The generated bundles contains a preinitialized Ethereum Account details. The account receives a stake delegation to the provider account with authorized beacon and tbtc application. This is a production-like experience for the Staking Providers, where they will receive stakes from their customers.

We have a scripts to create a bundle and initialize the provider account.

Please see README.md for more details.

Depends on https://github.com/keep-network/keep-core/pull/3211