Add service to change camera follow pgain.

[bperseghetti]

🦟 Bug fix

Fixes #514

Summary

Now you can set the pgain of the follow camera when following objects. This is needed for extremely high speed objects.

https://user-images.githubusercontent.com/10233412/215242320-eaa9d430-e853-49c6-a0de-81a69dc6c258.mp4

Checklist

• [x] Signed all commits for DCO
• [x] Added tests
• [x] Updated documentation (as needed)
• [x] Updated migration guide (as needed)
• [x] Consider updating Python bindings (if the library has them)
• [x] codecheck passed (See contributing)
• [x] All tests passed (See test coverage)
• [x] 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.

[ahcorde]

@osrf-jenkins run tests please!

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (8dae037) 72.98% compared to head (290c060) 69.18%. Report is 8 commits behind head on gz-gui7.

:exclamation: Current head 290c060 differs from pull request most recent head bea60bd. Consider uploading reports for the commit bea60bd to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## gz-gui7 #515 +/- ## =========================================== - Coverage 72.98% 69.18% -3.80% =========================================== Files 55 44 -11 Lines 4927 4930 +3 =========================================== - Hits 3596 3411 -185 - Misses 1331 1519 +188 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[mjcarroll]

@bperseghetti I haven't seen any movement on this one and it targets garden branches, so I'm going to remove the beta label for now.

[caguero]

@bperseghetti , friendly ping. Could you review the feedback and we'll try to merge this patch?

[bperseghetti]

@bperseghetti , friendly ping. Could you review the feedback and we'll try to merge this patch?

Yeah, will look it over again here this weekend and see if I can't make the requested changes.

[jennuine]

@bperseghetti there are CI errors:

/home/jenkins/workspace/gz_gui-ci-pr_any-focal-amd64/gz-gui/test/integration/follow_config.cc:162
Expected: (sleep) < (maxSleep), actual: 61 vs 60

[bperseghetti]

@bperseghetti there are CI errors:

/home/jenkins/workspace/gz_gui-ci-pr_any-focal-amd64/gz-gui/test/integration/follow_config.cc:162
Expected: (sleep) < (maxSleep), actual: 61 vs 60

I actually was planning to close this and open a new PR that has a more "holistic" approach to controlling the follow camera including what was done in here but more.

I just need to rebase that work on humble as I no longer plan to target it to garden (due to relatively sooner EOL).

[bperseghetti]

Closing in favor of PR #619