Update some tests to be independent of entity ordering (backport #3592)

[mergify]

🎉 New feature

Span out of #3447

Summary

Update the most straightforward tests to make them independent of order of entity in Each.
Both tests check that a query contains all the entities that should be present (i.e. a world has all the required models, model all the required links, link all the required collisions / visuals). However, it expects them to be in a specific order that is more of an implementation detail.
This PR, span out of the entt refactor, updates the tests so they still validate that all the entities are present but don't test anymore that they are iterated in a specific order.

Test it

Tested by CI, or run the affected tests manually

Checklist

• Signed all commits for DCO
• Added a screen capture or video to the PR description that demonstrates the feature
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• Updated Bazel files (if adding new files). Created an issue otherwise.
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---

This is an automatic backport of pull request #3592 done by Mergify.

[mergify]

Cherry-pick of 12219ac has failed:

On branch mergify/bp/ign-gazebo6/pr-3592
Your branch is up to date with 'origin/ign-gazebo6'.

You are currently cherry-picking commit 12219acb.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   src/SdfGenerator_TEST.cc
	modified:   test/integration/recreate_entities.cc
	modified:   test/integration/velocity_control_system.cc

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   src/SdfEntityCreator_TEST.cc
	both modified:   src/SimulationRunner_TEST.cc

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally