CheckTx msg routing

[fedekunze]

Fixes: #4639

• 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 a relevant changelog entry: clog add [section] [-t <tag>] [-m <msg>]

• Re-reviewed Files changed in the github PR explorer

---

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 #4810 into master will decrease coverage by 0.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #4810      +/-   ##
==========================================
- Coverage    50.5%   50.49%   -0.02%     
==========================================
  Files         288      288              
  Lines       18518    18516       -2     
==========================================
- Hits         9353     9349       -4     
- Misses       8480     8482       +2     
  Partials      685      685

[alexanderbez]

ACK