Add batch_update_form MCP tool that exposes the Google Forms
batchUpdate API endpoint. Supports createItem, updateItem,
deleteItem, moveItem, updateFormInfo, and updateSettings operations.
Includes _batch_update_form_impl internal function for testability
and 6 unit tests covering multiple requests, single request, empty
replies, missing replies key, URL generation, and mixed reply types.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
