x/distribution: register MsgFundCommunityPool

[fedekunze]

Description

closes: #6210

[auto-comment]

👋 Thanks for creating a PR!

Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

---

For contributor use:

• 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.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer

---

For admin use:

• Added appropriate labels to PR (ex. WIP, R4R, docs, etc)
• Reviewers assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

Thank you for your contribution to the Cosmos-SDK! 🚀

[alexanderbez]

ACK

[codecov]

Codecov Report

Merging #6211 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #6211   +/-   ##
=======================================
  Coverage   54.86%   54.86%           
=======================================
  Files         444      444           
  Lines       26787    26788    +1     
=======================================
+ Hits        14697    14698    +1     
  Misses      11048    11048           
  Partials     1042     1042