x/distribution: fix module's parameters validation

[alessio]

closes: #8914

---

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.

• 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
• Review Codecov Report in the comment section below once CI passes

[orijbot]

Benchmark beginning. Status page: https://github.orijtech.com/benchmark/status?commit=af872fe5f64c7948d234bb1d69a69188b81ed08f

[robert-zaremba]

utACK

[alexanderbez]

🎉

[orijbot]

Benchmark beginning. Status page: https://github.orijtech.com/benchmark/status?commit=6fa12a9c2bff3e7f1fa2795f18f1c8dbdf351ba5

[orijbot]

Benchmark finished. See the result: https://github.orijtech.com/benchmark/result?id=46d19e00a00c4164bfba53cc89192943

[orijbot]

Benchmark beginning. Status page: https://github.orijtech.com/benchmark/status?commit=b01cd9a2ae0d79c2c9e58228550c8315b5e1f41a

[orijbot]

Benchmark finished. See the result: https://github.orijtech.com/benchmark/result?id=366e964a6dbc447cba8b9cfb917d6b60

[alessio]

@zmanian @shahankhatch this looks state-breaking, i.e. parameters that were valid before will no longer be so once this patch is merged in. It must be said that even though this patch might potentially break applications state, any application that uses such invalid parameters would be anyway misusing the distribution module.

Here is the conundrum: should we backport it and include it in v0.42.2 or should we be gentle and mindful about those clients who misuse the Cosmos SDK?

[codecov]

Codecov Report

Merging #8918 (b01cd9a) into master (0836361) will increase coverage by 0.06%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #8918      +/-   ##
==========================================
+ Coverage   59.17%   59.24%   +0.06%     
==========================================
  Files         571      571              
  Lines       31807    31807              
==========================================
+ Hits        18822    18844      +22     
+ Misses      10782    10760      -22     
  Partials     2203     2203              

Impacted Files	Coverage Δ
x/distribution/types/params.go	81.25% <100.00%> (+34.37%)	⬆️

[orijbot]

Benchmark finished. See the result: https://github.orijtech.com/benchmark/result?id=2e20265a9a9a4dfeaf80d42b52612818

[orijbot]

Benchmark beginning. Status page: https://github.orijtech.com/benchmark/status?commit=1fddce73b361e1b9442811e36a401e8501a87468