Re-work CLI implementation to use Click

[amaslenn]

Summary

Click is a popular CLI building library in python community, so this change aims:

1. Simplify CloudAI's CLI implementation and reduce maintenance cost. We don't need maintain this code anymore and rely on tested framework.
2. Provide community-accepted way to re-use CLI for tools that consume CloudAI as a library. Click is highly composable, so users can extend it if needed.

This change introduces the only user-facing difference compared to previous CLI: --test-scenario is now mandatory for install and uninstall commands, so installing all components for the whole tests directory is not possible now. But with new install-during-run functionality that shouldn't be an issue.

Test Plan

1. CI (updated).
2. Manual runs of different commands.

Additional Notes

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