Promote cloud-init schema (SC-953)

[holmanb]

Promote schema command from devel to top level subcommand

[TheRealFalcon]

Some really nice changes here. Normally I like small updates along the way, but it looks like there's more non-schema changes than there are schema ones. Do you mind moving the misc updates to another PR?

Additionally, there's some other places that need to be updated.

• If you search for "devel schema" in faq.rst, tutorial.rst, and tests/integration_tests/modules/test_cli.py, they all need updates.
• Search '"devel", "schema"' in tests/unittests/test_cli.py
• cli.rst has schema documentation under the devel heading.
• bash_completion/cloud-init has schema is under devel

[holmanb]

Some really nice changes here. Normally I like small updates along the way, but it looks like there's more non-schema changes than there are schema ones. Do you mind moving the misc updates to another PR?

No problem. Agreed, this is snowballing a bit.

Additionally, there's some other places that need to be updated.

Thanks. I'll fix those as well.

[holmanb]

Note: I had to rebase for dropping commits, hence the force push. Since I already had to force push, I squashed the recommended "drop devel schema" change into the promotion commit since they overlapped.

Assuming this CI run passes, I think it should be ready for re-review.

[TheRealFalcon]

LGTM, thanks!

I trust you can fix the flake8 and spell check issue without another review.

[holmanb]

After rerunning CI passes, merging.