refactor(x/ecocredit): update to single basket fee param

[ryanchristo]

Description

Ref: #1359

This pull request updates the new basket fee ORM param to a single basket fee. When the basket fee is not set, no basket fee is required. The proto breaking changes are only breaking changes to the current revision.

Manual Testing: #1465 (comment)

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Author Checklist

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• included the correct type prefix in the PR title
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• included the necessary unit and integration tests
• added a changelog entry to CHANGELOG.md
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• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
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• reviewed state machine logic
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage
• manually tested (if applicable)

[codecov]

Codecov Report

Merging #1465 (3a63f0e) into main (2da88f6) will increase coverage by 0.01%.
The diff coverage is 88.28%.

@@            Coverage Diff             @@
##             main    #1465      +/-   ##
==========================================
+ Coverage   78.21%   78.23%   +0.01%     
==========================================
  Files         243      243              
  Lines       18626    18628       +2     
==========================================
+ Hits        14568    14573       +5     
+ Misses       3206     3204       -2     
+ Partials      852      851       -1     

Impacted Files	Coverage Δ
x/ecocredit/client/query.go	0.00% <0.00%> (ø)
x/ecocredit/client/tx.go	0.00% <0.00%> (ø)
...ecocredit/basket/types/v1/msg_update_basket_fee.go	62.50% <70.00%> (+12.50%)	⬆️
x/ecocredit/basket/keeper/query_fees.go	62.50% <75.00%> (+8.65%)	⬆️
x/ecocredit/basket/keeper/msg_create.go	83.84% <86.95%> (+0.51%)	⬆️
types/coin.go	90.62% <100.00%> (+6.41%)	⬆️
x/ecocredit/base/keeper/query_params.go	56.00% <100.00%> (ø)
x/ecocredit/basket/client/query.go	72.51% <100.00%> (ø)
x/ecocredit/basket/keeper/msg_update_basket_fee.go	80.00% <100.00%> (-2.36%)	⬇️
x/ecocredit/client/testsuite/grpc_basket.go	100.00% <100.00%> (ø)
... and 8 more

[aleem1314]

lgtm

[ryanchristo]

Manual Tests: https://hackmd.io/l6wc4t_WS2iFE1TJTk_1oA. Everything works as expected.