How can I trigger a PR preview programatically

### Amplify CLI Version

latest

### Question

Firebase Hosting allows users to [create a Preview deployment through their CLI](https://firebase.google.com/docs/hosting/test-preview-deploy#preview-channels). They even have the option to [delete previews](https://firebase.google.com/docs/hosting/manage-hosting-resources#delete-preview-channel). Does the Amplify CLI have a similar feature?

A feature like this is critical when optimising CI/CD pipelines. If certain quality checks don't pass or other automation is not completed (for example if a PR is not ready for review) - we don't need to deploy a preview.

No implementation files, tests, or command entry points are identified in the issue. Start by tracing the Amplify CLI's deployment commands and CI/CD behavior, then determine the supported preview lifecycle and define completion criteria for creating and deleting previews programmatically.

Written by the indexing model from the issue text.