chore: decouple x/feegrant and simapp

[julienrbrt]

Description

Ports #12366 to main
cc @facundomedica

---

Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
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
• confirmed all CI checks have passed

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 #12388 (d5c45f5) into main (99b21ab) will decrease coverage by 0.15%.
The diff coverage is 92.30%.

@@            Coverage Diff             @@
##             main   #12388      +/-   ##
==========================================
- Coverage   65.83%   65.67%   -0.16%     
==========================================
  Files         677      676       -1     
  Lines       71496    71429      -67     
==========================================
- Hits        47070    46912     -158     
- Misses      21783    21877      +94     
+ Partials     2643     2640       -3     

Impacted Files	Coverage Δ
x/feegrant/module/module.go	44.94% <0.00%> (-11.24%)	⬇️
x/feegrant/client/testutil/suite.go	88.36% <100.00%> (-11.30%)	⬇️
x/feegrant/simulation/operations.go	83.63% <100.00%> (ø)
core/appconfig/config.go