Feature Request: Support for Mocking Activity Responses in Step Functions Local

[waterfallmouse]

Hello,

I recently encountered an issue while trying to mock responses for Activity states in AWS Step Functions Local. When attempting to do so, I received the following error:

{
    "timestamp": "2024-01-16T14:31:11.066000+09:00",
    "type": "ExecutionFailed",
    "id": 19,
    "executionFailedEventDetails": {
        "error": "States.Runtime",
        "cause": "Activity state cannot be mocked. Please remove mocks mapped for all activity state in the mock config file."
    }
}

This error indicates that it's currently not possible to mock Activity states, which I found to be a limitation in testing scenarios where activities play a crucial role.

I would like to request the feature to allow mocking responses for Activity states in Step Functions Local. This enhancement would be incredibly beneficial for developers who need to test their Step Functions locally, especially in complex workflows where Activities are used extensively.

Adding this functionality would greatly enhance the testing capabilities and overall developer experience when working with Step Functions in a local development environment.

Thank you for considering this request. I am looking forward to any updates on this feature.

Best regards,