[Request]: Add YAML output format option for CLI commands

[manojmahapatra]

Feature or enhancement request details

Currently, commands like container system version, container list, container image list, etc. support --format table and --format json.
Would it be worth adding --format yaml as an option?

Example output: container system version --format yaml:

yaml
- version: "0.9.0"
  buildType: release
  commit: abc1234
  appName: container
- version: "0.9.0"
  buildType: release
  commit: abc1234
  appName: API Server

If there's enough interest, I'd be happy to work on a proposal and implementation to add this.

Code of Conduct

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[jglogan]

@manojmahapatra I'd be okay with this. What library would you use for the YAML serialization?

Also, don't do one PR that implements it across the board. Best would be to do one PR per resource, starting with the registry resources after we get #1138 and #1119 merged.

[jglogan]

Just need #1119 now.

[manojmahapatra]

@jglogan Thank you for looking into it. For YAML serialization, I'd use Yams which is already used by other OSS projects like swift-configuration.

Happy to break this into incremental PRs per resource. I will wait for #1119 to land.