[ECS] [request]: Expose Deployment status via metrics and appropriate CLI command

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**Tell us about your request**
Introduce and expose Deployment metrics from ECS control plane via:
1. CloudWatch metrics
2. Appropriate changes to `aws ecs wait` or possibly introduce a new CLI command to track the deployment status.

**Which service(s) is this request for?**
ECS

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
It is almost impossible to track failed deployments using the ECS control plane. We have to utilize AWS Lambda to poll the status of the rolled out tasks. The `aws ecs wait` does not fit the purpose if the service is using a circuit breaker. The lack of dedicated metrics is also making this harder from the CloudWatch perspective. Hence we rolled out AWS Lambda which checks that the latest Task Definition is in production.

**Are you currently working around this issue?**
Using AWS Lambda to inspect the newly rolled out tasks match the latest Task Definition. The AWS Lambda is invoked from the CI/CD.

**Additional context**
.

**Attachments**