This changes makes it so that we output the empty string for Format
when there is no data. It turns out there are many places in the code
where we have such handling, but in a way that would break the JSON
formatter (since we'd output nothing on stdout or text rather than
`[]`/`null`).
What this changes:
- Unhides the `--key` flag on provisioner start
- Deprecates and hides `provisionerd` command group in favor of
`provisioner(s)`
- Removes org id from `coder provisioner keys list`