Port ObjectSet Tests

[erdii]

Summary

• fix(vscode): manually set integration build tag for gopls integration
• chore(linter): disable long-line-linter for go comments
• chore(tests): port ObjectSet integration tests to boxcutter RevisionEngine
• chore: require correct discovery client interface instead of pointer to concrete discovery client
• chore: clean up some typos
• fix(reference): always set object namespace to owner's namespace

The main goal of this PR is to port the ObjectSet integration tests from package operator.

Change Type

Check List Before Merging

• This PR passes all pre-commit hook validations.
• This PR is fully tested and regression tests are included.
• Relevant documentation has been updated.

Additional Information

[codecov]

Codecov Report

Attention: Patch coverage is 83.11688% with 13 lines in your changes missing coverage. Please review.

Project coverage is 44.60%. Comparing base (fe4da57) to head (02b134c).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
test/test_util.go	81.66%	7 Missing and 4 partials ⚠️
cmd/reference/internal/deploy.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #121      +/-   ##
==========================================
+ Coverage   40.46%   44.60%   +4.13%     
==========================================
  Files          27       29       +2     
  Lines        2753     2825      +72     
==========================================
+ Hits         1114     1260     +146     
+ Misses       1536     1458      -78     
- Partials      103      107       +4     

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