aws-applicationautoscaling: Missing treatmissingdata attribute in `BasicStepScalingPolicyProps`

### Describe the bug

When defining a step scaling policy for a fargate service, the `BasicStepScalingPolicyProps` doesn't allow for the specification of how to treat the missing data for the alarms that are created. I imagine that it's because it's potentially creating several alarms and we don't want them having the same behaviour. But I couldn't find a way to find the alarms created to then add that afterwards.
I'm scaling up and down depending on the ApproximateNumberOfMessagesVisible in an SQS, but the metric doesn't return a datapoint when it's empty (instead of 0).

### Expected Behavior

We have a way to specify how the alarms treat the missing data.

### Current Behavior

The attribute doesn't exist and we can't get the alarms created with `scaleOnMetric`. The default on the alarms is to treat the missing data as missing.

### Reproduction Steps

1. Create a fargate service
2. call `autoScaleTaskCount`
3. call `scaleOnMetric`

### Possible Solution

_No response_

### Additional Information/Context

_No response_

### CDK CLI Version

2.37.1

### Framework Version

_No response_

### Node.js Version

16.15.1

### OS

Mac OS

### Language

Typescript

### Language Version

Typescript (4.7.4)

### Other information

_No response_

Start by locating BasicStepScalingPolicyProps and scaleOnMetric in the aws-applicationautoscaling implementation, then trace how the alarms for step scaling are created. Check the related package tests before making a change. Done means callers can specify how those alarms treat missing data and the behavior is covered by tests.

Written by the indexing model from the issue text.