Support for sending funds to the community pool

[RiccardoM]

Description

Closes #5206

To do

• Add tests
• Add tx command
• Add documentation

Checklist

• 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 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, ready-for-review, docs)
• Reviewers Assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[codecov]

Codecov Report

Merging #5249 into master will increase coverage by 0.08%.
The diff coverage is 30.88%.

@@            Coverage Diff             @@
##           master    #5249      +/-   ##
==========================================
+ Coverage   54.55%   54.64%   +0.08%     
==========================================
  Files         311      311              
  Lines       18653    18529     -124     
==========================================
- Hits        10176    10125      -51     
+ Misses       7700     7631      -69     
+ Partials      777      773       -4

Impacted Files	Coverage Δ
simapp/test_helpers.go	0% <0%> (ø)	⬆️
x/distribution/client/cli/tx.go	4.76% <0%> (-0.8%)	⬇️
x/distribution/handler.go	7.14% <0%> (-1.63%)	⬇️
simapp/app.go	90.06% <100%> (+0.31%)	⬆️
x/distribution/types/msg.go	56.92% <58.82%> (+0.67%)	⬆️
x/distribution/keeper/keeper.go	82.71% <71.42%> (-1.07%)	⬇️
x/params/subspace/subspace.go	0% <0%> (-77.36%)	⬇️
x/params/subspace/table.go	74.35% <0%> (-25.65%)	⬇️
x/params/proposal_handler.go	62.96% <0%> (-10.73%)	⬇️
x/mock/app.go	62.83% <0%> (-1.36%)	⬇️
... and 15 more

[alexanderbez]

Thanks @RiccardoM, I would like to see the following:

1. A changelog entry
2. A test case testing you can send to the community pool address and only that address

Thanks for the contribution!

[RiccardoM]

Thanks @RiccardoM, I would like to see the following:

1. A changelog entry
2. A test case testing you can send to the community pool address and only that address

Thanks for the contribution!

I've implemented the tests. The only thing missing is the changelog. Under which section and tag should I put it?

[alexanderbez]

ACK -- @RiccardoM you can simply add the following under Features and state-machine-breakingin the changelog:

* (modules) [\#5249](https://github.com/cosmos/cosmos-sdk/pull/5249) Funds are now allowed to be directly sent to the community pool (via the distribution module account).

[RiccardoM]

ACK -- @RiccardoM you can simply add the following under Features and state-machine-breakingin the changelog:

* (modules) [\#5249](https://github.com/cosmos/cosmos-sdk/pull/5249) Funds are now allowed to be directly sent to the community pool (via the distribution module account).

Done! :D

[alexanderbez]

Apologies @RiccardoM, but after testing this, I've realized that this solution is not correct as it turns out that the community fund pool is unique and not an actual module account.

We'll need to adjust this PR slightly. We'll need a custom message type that sends funds from an account to the distribution module account AND also adds the funds to the pool itself:

k.supplyKeeper.SendCoinsFromAccountToModule(ctx, sender, types.ModuleName, amount)
feePool.CommunityPool = feePool.CommunityPool.Add(amount)
k.SetFeePool(ctx, feePool)

[alexanderbez]

@RiccardoM do you need assistance on this PR? We can complete it together if you wish.

[RiccardoM]

@alexanderbez Sorry, been very busy with other stuff. It should be mostly done now

[alexanderbez]

Looks great @RiccardoM -- just a few bits of minor feedback.

[alexanderbez]

ACK -- I think the message type name can change, but we can do that in another PR.

[fedekunze]

Minor nits mostly. Please add the msg validation on the cli as well

[alexanderbez]

I'm addressing all comments in a subsequent PR @fedekunze + adding support for simulation.