feat: Add tx encode and decode endpoints for amino txs

[likhita-809]

Description

Closes: #10856
ref: #13085

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[codecov]

Codecov Report

Merging #13882 (64fc64c) into main (2739f83) will increase coverage by 0.06%.
The diff coverage is 0.00%.

❗ Current head 64fc64c differs from pull request most recent head 885ad11. Consider uploading reports for the commit 885ad11 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #13882      +/-   ##
==========================================
+ Coverage   56.25%   56.32%   +0.06%     
==========================================
  Files         667      673       +6     
  Lines       56576    56913     +337     
==========================================
+ Hits        31829    32055     +226     
- Misses      22165    22254      +89     
- Partials     2582     2604      +22     

Impacted Files	Coverage Δ
x/auth/tx/service.go	0.00% <0.00%> (ø)
x/distribution/simulation/operations.go	80.64% <0.00%> (-9.68%)	⬇️
x/group/module/module.go	48.05% <0.00%> (-0.10%)	⬇️
server/mock/tx.go	53.33% <0.00%> (ø)
x/auth/types/codec.go	100.00% <0.00%> (ø)
x/group/keeper/migrations.go
x/auth/types/credentials.go
x/group/migrations/v2/migrate.go
tx/textual/valuerenderer/message.go	64.22% <0.00%> (ø)
tx/textual/valuerenderer/timestamp.go	89.28% <0.00%> (ø)
... and 12 more

[amaury1093]

We should unmarshal amino_json first, then marshal it back.

[tac0turtle]

thank you, could we get a changelog and then we should add it to a client section in docs if we have a section .

[likhita-809]

thank you, could we get a changelog and then we should add it to a client section in docs if we have a section .

added changelog, the client docs should go here

[julienrbrt]

lgtm!

[amaury1093]

There's still some confusion between amino binary and amino JSON in this PR. @likhita-809 I'll let you address the comments, but ping me on Slack if you have questions

[sonarcloud]

[Cosmos SDK] Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

95.2% Coverage
0.0% Duplication

[amaury1093]

LGTM, thanks!