Update SDK to Support New ERC20Handler with Optional Contract Call

[MakMuftic]

Implementation details

With the introduction of the new ERC20Handler, the SDK needs to be updated to handle the enhanced functionality that supports both ERC20 token transfers and optional contract calls in a single transaction. New ERC20Handler PR

• Modify the SDK to work with the updated ERC20Handler by allowing it to handle additional data that encodes contract calls alongside ERC20 transfers.
• Maintain compatibility with existing handlers and workflows that do not involve contract calls, ensuring that the SDK remains functional for all users.

Testing details

• Unit Tests: Develop unit tests that cover scenarios where both ERC20 transfers and contract calls are involved.
• Compatibility Tests: Ensure that existing functionality remains unaffected by the changes.
• Error Handling: Test how the SDK handles invalid or failed contract calls within the transaction flow.

Acceptance Criteria

• The SDK supports interactions with the new ERC20Handler, allowing for both ERC20 transfers and optional contract calls within the same transaction.
• The SDK maintains backward compatibility and continues to function as expected with existing handlers.
• All new functionality is covered by tests, ensuring reliable and consistent behavior.