Update camera sensors to use the `//sensor/camera/pose` sdf element.

[iche033]

🦟 Bug fix

Summary

Follow-up on https://github.com/gazebosim/gz-sim/pull/2425#issuecomment-2148165722. This is a behavior change so targeting main. The camera sensors will now take into account the //sensor/camera/pose sdf element. I also added an entry to Migration guide.

Checklist

• [x] Signed all commits for DCO
• [ ] Added tests
• [ ] 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)
• [ ] While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[azeey]

The //sensor/camera/pose element seems redundant with //sensor/pose. If we don't have a good reason to keep it, maybe it can be deprecated and removed from the SDFormat spec.

[iche033]

I'm in favor of deprecating and then removing the tag. Closing this PR