Return different error code for different error message

### Summary
Categorize different error messages and give them different error code. So customers can use it to implement their own handling logic.

### Description
One customer's use case:

The tasks that are running are getting intermittent "CannotPullContainer" errors and are failing the tasks instead of retrying the Container request due to the error code coming back from the API.

When the task fails, it would be better to return back a response code of 500 or retry the task.The cx has different retry codes that would handle the step function task if the status code was different. There does not seem to be a specific error code for “CannontPullContainer” at this time.

### Environment Details

### Supporting Log Snippets

No repository files, tests, or entry points are named. Start by tracing the CannotPullContainer response through the ECS task failure and Step Functions retry flow, then define the error categories and response codes; done means customers can distinguish this error and apply retry handling.

Written by the indexing model from the issue text.