command/views: Document and divide init JSON message types

[radeksimko]

I accept that omitting some of the message codes from the JSON messages may not have been the original intention but instead of nerd-sniping myself into changing it I am at least documenting the reality as I found it while documenting the init -json publicly in hashicorp/web-unified-docs#656

The documentation/descriptions may later be used in public-facing docs if we decide to use those message codes publicly.

Target Release

1.14.x

Rollback Plan

• If a change needs to be reverted, we will roll out an update to the code within 7 days.

Changes to Security Controls

Are there any changes to security controls (access controls, encryption, logging) in this pull request? If so, explain.

CHANGELOG entry

• This change is user-facing and I added a changelog entry.
• This change is not user-facing.

[SarahFrench]

Just to check- does internally here mean that these messages are not (yet) documented in the machine readable output pages in the 'Internals' documentation? Or is it that the output from using -json does some selections of what is rendered in a machine readable way?

[radeksimko]

I'm not sure if it was intentional - hence my note in the PR description but generally I found that any InitMessageCode which is passed down to either PrepareMessage or Log (as opposed to Output practically turn the message into a JSON object which does not have that code anymore and instead have type set to the generic log.

init command generally also does not use go-hclog to emit these messages, which makes it different from how plan/apply JSON output is implemented - also something to reconsider.

My aim here was to get things documented at least though, not to necessarily fix anything (yet).