R4R: Fix tag usage in handlers and EndBlocker

[hendrikhofstadt]

Closes #2941

The tags of the staking EndBlocker have been ignored by now and action tags were added twice for some transactions.

CC @cwgoes - could we get this in for v0.27.0 since this is a blocker for our block explorer?

• 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)

[codecov]

Codecov Report

Merging #2943 into develop will decrease coverage by 0.01%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop    #2943      +/-   ##
===========================================
- Coverage     56.3%   56.29%   -0.02%     
===========================================
  Files          120      120              
  Lines         8420     8411       -9     
===========================================
- Hits          4741     4735       -6     
+ Misses        3357     3354       -3     
  Partials       322      322

[cwgoes]

ACK; please add a PENDING.md entry, and we should fix the ability of invalid public keys to halt the state machine (#2945), but that can be done separately.

[alessio]

Looks good to me. Thanks!

[hendrikhofstadt]

@cwgoes Updated docs and pending 👍

[alexanderbez]

LGTM ❤️