feat: decouple x/group from simapp

[likhita-809]

Description

Closes: #12024

decouple x/group from simapp

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Author Checklist

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please add links to any relevant follow up issues.

I have...

• included the correct type prefix in the PR title
• added ! to the type prefix if API or client breaking change
• targeted the correct branch (see PR Targeting)
• provided a link to the relevant issue or specification
• followed the guidelines for building modules
• included the necessary unit and integration tests
• added a changelog entry to CHANGELOG.md
• included comments for documenting Go code
• updated the relevant documentation or specification
• reviewed "Files changed" and left comments if necessary
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Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
• confirmed all author checklist items have been addressed
• 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 #12277 (859d3f7) into main (7623603) will decrease coverage by 0.03%.
The diff coverage is 97.29%.

@@            Coverage Diff             @@
##             main   #12277      +/-   ##
==========================================
- Coverage   66.16%   66.12%   -0.04%     
==========================================
  Files         675      675              
  Lines       71272    71273       +1     
==========================================
- Hits        47156    47129      -27     
- Misses      21469    21499      +30     
+ Partials     2647     2645       -2     

Impacted Files	Coverage Δ
x/group/module/module.go	48.27% <0.00%> (-12.19%)	⬇️
x/group/simulation/operations.go	68.08% <100.00%> (ø)
x/group/keeper/invariants.go	42.64% <0.00%> (-10.30%)	⬇️
x/distribution/simulation/operations.go	80.43% <0.00%> (-9.79%)	⬇️
crypto/keys/internal/ecdsa/privkey.go	83.01% <0.00%> (+1.88%)	⬆️
x/group/keeper/keeper.go	57.38% <0.00%> (+2.95%)	⬆️

[julienrbrt]

lgtm!