refactor: Use mocks for x/authz testing

[likhita-809]

Description

Closes: #12761

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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
• 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 #12799 (acfab96) into main (2bb48e8) will decrease coverage by 0.06%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main   #12799      +/-   ##
==========================================
- Coverage   56.25%   56.19%   -0.07%     
==========================================
  Files         644      644              
  Lines       54933    54933              
==========================================
- Hits        30902    30867      -35     
- Misses      21541    21575      +34     
- Partials     2490     2491       +1     

Impacted Files	Coverage Δ
x/authz/keeper/migrations.go	0.00% <0.00%> (-50.00%)	⬇️
x/authz/module/module.go	17.50% <0.00%> (-35.00%)	⬇️
x/authz/keeper/keeper.go	68.72% <0.00%> (-2.32%)	⬇️
x/group/keeper/keeper.go	56.29% <0.00%> (+0.39%)	⬆️

[alexanderbez]

great work @likhita-809!!!

[JeancarloBarrios]

Nice

[tac0turtle]

utACK

[anilcse]

Snapshot tests are failing

[tac0turtle]

Snapshot tests are failing

related to go 1.19. Need to debug