feat: implement x/params get all subspaces/keys

[alexanderbez]

Description

closes: #9873

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Author Checklist

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• confirmed the correct type prefix in the PR title
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• reviewed state machine logic
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[orijbot]

Visit https://dashboard.github.orijtech.com?pr=9884&remote=false&repo=cosmos%2Fcosmos-sdk to see benchmark details.

[codecov]

Codecov Report

Merging #9884 (1231ded) into master (59f63a2) will increase coverage by 0.09%.
The diff coverage is 95.20%.

@@            Coverage Diff             @@
##           master    #9884      +/-   ##
==========================================
+ Coverage   63.50%   63.59%   +0.09%     
==========================================
  Files         568      568              
  Lines       53350    53490     +140     
==========================================
+ Hits        33879    34019     +140     
+ Misses      17549    17547       -2     
- Partials     1922     1924       +2     

Impacted Files	Coverage Δ
client/context.go	58.28% <ø> (+2.06%)	⬆️
x/params/keeper/grpc_query.go	73.68% <68.18%> (-7.57%)	⬇️
x/auth/client/testutil/suite.go	96.83% <100.00%> (+0.27%)	⬆️
x/params/keeper/keeper.go	82.35% <100.00%> (+5.42%)	⬆️
x/params/types/subspace.go	81.81% <100.00%> (+1.22%)	⬆️
crypto/keys/internal/ecdsa/privkey.go	84.21% <0.00%> (+1.75%)	⬆️

[anilcse]

lgtm