feat: add TransferMachineBalanceClass

[gonzalo-smtv]

This pull request adds a new class to handle the transfer of machine station balances using the ethers library. The changes include setting up the environment configuration, defining the contract and wallet details, and implementing the main functionality to sign and transfer balances.

Key changes include:

Environment Configuration:

• Imported necessary modules and set up environment variables for RPC URL, chain ID, contract address, and private keys.

Contract and Wallet Setup:

• Defined the contract address and created instances for the contract and wallet accounts using the ethers library.

Transfer Functionality:

• Implemented the TransferMachineBalanceClass with methods to generate a random nonce, sign the transfer data, and send the transaction.
• Added a helper function sendTransaction to sign and send transactions to the blockchain.

Execution Script:

• Created an execution script to instantiate the TransferMachineBalanceClass and call the transferBalance method, handling any errors that occur.