R4R: Minor changes on slashing logs and gov Querier

[fedekunze]

Part 2 of the split process from #2139.
This one adds constants to queriers and has minor changes to logs for better readability.

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• Targeted PR against correct branch (see CONTRIBUTING.md)

• 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 #

• Reviewed 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]

Thanks @fedekunze -- I left some feedback on how I think the logs could change slightly. Otherwise, LGTM 👍

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (develop@e5e7c4f). Click here to learn what that means.
The diff coverage is 50%.

@@            Coverage Diff             @@
##             develop    #2259   +/-   ##
==========================================
  Coverage           ?   63.88%           
==========================================
  Files              ?      140           
  Lines              ?     8694           
  Branches           ?        0           
==========================================
  Hits               ?     5554           
  Misses             ?     2758           
  Partials           ?      382

addressed

[alexanderbez]

One more minor thing @fedekunze -- thanks!

[alexanderbez]

utACK -- attempt a merge of develop @fedekunze to resolve any CI issues.

[cwgoes]

utACK