[FEATURE] [Coinswap] Create Taker RPC Handlers

[hulxv]

Description

Implement all Taker RPC handlers using mill-rpc framework.

Motivation

Port all existing Taker functionality to the new framework with improved error handling and performance.

Proposed Solution

• create_swap
• get_swap_status
• list_swaps
• cancel_swap
• get_balance
• get_new_address
• send_payment

Tasks

• Implement create_swap handler
• Implement get_swap_status handler
• Implement list_swaps handler
• Implement cancel_swap handler
• Implement wallet handlers
• Add proper error handling
• Write unit tests for each handler
• Document handler behavior

Expected

• All Taker RPC endpoints functional
• Improved error handling
• Type-safe parameter handling
• Comprehensive test coverage