Port IsAllGT from safe-coins PR

[alessio]

See #3678

• Linked to github-issue with discussion and accepted design OR link to spec that describes this work.
• Wrote tests
• Updated relevant documentation (docs/)
• Added entries in PENDING.md with issue #
• rereviewed Files changed in the github PR explorer

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For Admin Use:

• Added appropriate labels to PR (ex. wip, ready-for-review, docs)
• Reviewers Assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[alexanderbez]

Missing a bug fix pending log entry, but otherwise LGTM. Also a note on the function name :)

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (sunny/coins-AllGT-test@714168f). Click here to learn what that means.
The diff coverage is 100%.

@@                    Coverage Diff                    @@
##             sunny/coins-AllGT-test    #3826   +/-   ##
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  Coverage                          ?   60.99%           
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  Files                             ?      192           
  Lines                             ?    14321           
  Branches                          ?        0           
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  Hits                              ?     8735           
  Misses                            ?     5019           
  Partials                          ?      567

[alessio]

@alexanderbez

Missing a bug fix pending log entry

This PR goes into Sunny's branch, PENDING.md will be amended there.