feat: add support for Batch amendment

[mvadari]

High Level Overview of Change

This PR:

• Adds models for the Batch transactions
• Updates definitions.json to handle the new field types
• Adds support to the binary codec to properly sign multi-account Batch transactions
• Adds helper functions for signing and combining multi-account Batch transactions
• Adds support to autofill for filling in the BatchTxn and TxIDs fields
• Adds support for Batchnet to the faucets

Context of Change

XRPLF/rippled#5060

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Refactor (non-breaking change that only restructures code)
• Tests (You added tests for code that already exists, or your new feature included in this PR)
• Documentation Updates
• Release

Did you update HISTORY.md?

• Yes
• No, this change does not impact library users

Test Plan

Added tests for the new features.

[mvadari]

Integration tests are expected to fail, since there is an integration test for Batch (which is not in the Docker container yet).