Initial implementation for CreateContainer()

[OneBlue]

Summary of the Pull Request

This change introduces an initial "native" implementation of CreateContainer(), along with --container and --debug-shell options for wsl --wsla.

A lot still needs to be done in WSLAContainer, but this is a good starting point.

This change is based on @ptrivedi's initial CreateContainer PR: https://github.com/microsoft/WSL/pull/13758

PR Checklist

• [ ] Closes: Link to issue #xxx
• [ ] Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
• [X] Tests: Added/updated if needed and all pass
• [ ] Localization: All end user facing strings can be localized
• [ ] Dev docs: Added/updated if needed
• [ ] Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed