feat: setting protocol controlled min gas price

[robert-zaremba]

Description

Closes: #1214

This is a "v1" solution for requiring min-gas price. More flexible mechanism (#1017) we will develop for v4 (or v5).

Notes:

• added fee-notes.md files with stats for the fees.

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Author Checklist

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• included the correct type prefix in the PR title
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• added a changelog entry to CHANGELOG.md
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[codecov-commenter]

Codecov Report

Merging #1326 (fc9fc23) into main (5cbf948) will increase coverage by 0.24%.
The diff coverage is 96.77%.

@@            Coverage Diff             @@
##             main    #1326      +/-   ##
==========================================
+ Coverage   52.22%   52.46%   +0.24%     
==========================================
  Files          69       70       +1     
  Lines        6836     6877      +41     
==========================================
+ Hits         3570     3608      +38     
- Misses       2988     2990       +2     
- Partials      278      279       +1     

Impacted Files	Coverage Δ
ante/spam_prevention.go	75.92% <0.00%> (-1.44%)	⬇️
x/leverage/client/tests/suite.go	95.45% <93.33%> (-0.20%)	⬇️
ante/fee.go	90.29% <95.74%> (+0.54%)	⬆️
util/genmap/genmap.go	100.00% <100.00%> (ø)
x/leverage/client/tests/tests.go	100.00% <100.00%> (ø)
x/leverage/module.go	58.73% <100.00%> (ø)
x/leverage/simulation/operations.go	76.95% <100.00%> (-1.07%)	⬇️
x/oracle/client/tests/suite.go	98.38% <100.00%> (ø)
x/oracle/keeper/keeper.go	84.50% <100.00%> (ø)

[adamewozniak]

lgtm! @RafilxTenfen asked the questions I was going to lol

might be worth adding changelog here @robert-zaremba

[adamewozniak]

@RafilxTenfen can you check on why the v1->v3 test is failing? https://github.com/umee-network/umee/runs/8257796548?check_suite_focus=true

I think everything else is g2g