[Feature Request] `az pipelines preview` command

**Is your feature request related to a problem? Please describe.**
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I would like the ability to generate fully expanded azure pipelines templates using the [Pipelines Preview](https://learn.microsoft.com/en-us/rest/api/azure/devops/pipelines/preview/preview?view=azure-devops-rest-7.1) API. The `az pipelines` command does not have a `preview` subcommand.

**Describe the solution you'd like**
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I would like the `az pipelines preview` command to be added which would allow providing an azure pipelines YML file and would return the fully expanded pipeline YAML file.

ideally, you would provide `id`, `branch` instead of actual YAML to the command, but also allowing a `yamlOverride` would be nice as well.

**Additional context**
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We are wanting a way to programmatically receive a fully expanded Azure pipelines YAML.