cli: improve autocompletions for various commands

[tgross]

Some commands are missing autocompletion flags for specific fields, have completions for flags that are deprecated or no longer exist, have the wrong predictor, or don't perform searches for argument completions for objects from state.

This is one of three batches of work to improve autocompletions, focusing on a miscellaneous set of commands.

Generative AI disclosure: as part of an ongoing pilot, this changeset was partially generated via Claude Code with the exception of the code reuse refactoring and minor touch-ups. Reviewed and tested manually, with commit description written by human for humans.

Ref: #27507
Ref: #27505

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• Changelog Entry If this PR changes user-facing behavior, please generate and add a
  changelog entry using the make cl command.
• Testing Please add tests to cover any new functionality or to demonstrate bug fixes and
  ensure regressions will be caught.
  • as this is a UX improvement, this was tested manually
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  Please also consider whether the change requires notes within the upgrade
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Changes to Security Controls

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

[jrasell]

LGTM!

[jrasell]

Wondering if we wanted to point of what grouping of commands, so the changelog entry doesn't clash with the other PR's in this piece of work.

[tgross]

#27505 is new autocompletions where they didn't exist before, whereas #27507 overlaps with this one a lot and the division was fairly arbitrary for keeping review size down. I sort of intended for this changelog entry to cover both this and #27507 which is why I kept this vague rather than listing dozens of commands. What do you think?