R4R: Remove --select in block command

[mslipper]

Closes #1968.

• Linked to github-issue with discussion and accepted design OR link to spec that describes this work.
• Updated all relevant documentation (docs/)
• Updated all relevant code comments
• Wrote tests
• Added entries in PENDING.md that include links to the relevant issue or PR that most accurately describes the change.
• Updated cmd/gaia and examples/

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For Admin Use:

• Added appropriate labels to PR (ex. wip, ready-for-review, docs)
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[mslipper]

I saw a TODO that said 'actually honor --select' that I removed... I suggest we instead track that in a GitHub issue as opposed to a TODO comment. I'm also happy to implement that if that'll be more valuable than this PR, just let me know.

[codecov]

Codecov Report

Merging #2060 into develop will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop    #2060   +/-   ##
========================================
  Coverage    63.83%   63.83%           
========================================
  Files          113      113           
  Lines         6684     6684           
========================================
  Hits          4267     4267           
  Misses        2133     2133           
  Partials       284      284

[alexanderbez]

utACK -- I suggest creating a new issue and reference that here (for honoring --select 👍

[cwgoes]

Thanks; please rebase against develop and check the CI failures.

[jaekwon]

LGTM

CI passes