Implement MarshalJSON for Coins Type

[alexanderbez]

When coins are nil, they are JSON encoded as null in responses which is a bad UX for API and client consumers. This PR implements a custom JSON marshaler that encodes nil coins as []. Decoding remains unchanged and behavior is left intact.

closes: #4259

/cc @vikmeup

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• Wrote tests

• Updated relevant documentation (docs/)

• Added a relevant changelog entry: clog add [section] [stanza] [message]

• rereviewed Files changed in the github PR explorer

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[codecov]

Codecov Report

Merging #4454 into master will increase coverage by 0.05%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #4454      +/-   ##
==========================================
+ Coverage   54.63%   54.69%   +0.05%     
==========================================
  Files         250      250              
  Lines       16061    16065       +4     
==========================================
+ Hits         8775     8786      +11     
+ Misses       6641     6634       -7     
  Partials      645      645

Impacted Files	Coverage Δ
types/coin.go	90.49% <100%> (+0.85%)	⬆️
x/mock/app.go	61.49% <0%> (+1.24%)	⬆️
types/codec.go	100% <0%> (+100%)	⬆️

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[alexanderbez]

@vikmeup We'll get this in the next point release v0.34.7.

[kolya182]

@alexanderbez Thank you for fixing it, but RPC still returns wrong https://stargate.cosmos.network/auth/accounts/cosmos1633n6ga6zee5nz2uhtsn5urug8qzxthmz85ne9

[alexanderbez]

That's because we haven't included it in a release yet @kolya182. We will soon :)

[kolya182]

@alexanderbez Do you have ETA for soon ?

[alexanderbez]

@kolya182 end of next week.

[kolya182]

@kolya182 end of next week.

How about now ?

[kolya182]

@alexanderbez How about this week ?

[alexanderbez]

@kolya182 yes, we're going to be cutting a RC today. I anticipate we'll have a full release next week 👍

Sorry for any inconvenience.

[kolya182]

@alexanderbez Will you roll out update to https://github.com/cosmos/gaia repo ?

[alexanderbez]

@kolya182 SDK v0.36.0-rc1 and Gaia v1.0.0-rc1 have been cut. If the testnet operates smoothly, I anticipate we'll have a final release next week. Sorry for the delay!

[kolya182]

@alexanderbez It's even worst now https://stargate.cosmos.network/bank/balances/cosmos1nk2aalgqtr2tjraqzygtwq5t4dan2rtwvs5fhg

[alexanderbez]

@kolya182 stargate is pointing to mainnet, not the testnet (which is running the latest version).

[kolya182]

@kolya182 stargate is pointing to mainnet, not the testnet (which is running the latest version).

When mainnet ?

[alexanderbez]

When mainnet ?

https://www.mintscan.io/proposals/13