Fix CMake version examples and bump plugin version

[methylDragon]

🦟 Bug fix

Related to: gazebo-tooling/release-tools#700

Summary

Use *_VERSION_MAJOR variables to aid search/replace scripts.
Also bumps the version.

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• 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

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[methylDragon]

Not sure why the CI is breaking... It broke for the commit when I just had docs changes.

[scpeters]

this will need to be merged to main before the version bumps can be done

[methylDragon]

Is it an issue if CI seems to be failing? Required CI pass though.

229:   File "/Users/jenkins/workspace/ignition_gazebo-ci-pr_any-homebrew-amd64/ign-gazebo/python/test/testFixture_TEST.py", line 21, in <module>
229:     from ignition.math import Vector3d
229: ModuleNotFoundError: No module named 'ignition.math'

https://build.osrfoundation.org/job/ignition_gazebo-ci-pr_any-homebrew-amd64/8052/console

[scpeters]

Is it an issue if CI seems to be failing? Required CI pass though.

229:   File "/Users/jenkins/workspace/ignition_gazebo-ci-pr_any-homebrew-amd64/ign-gazebo/python/test/testFixture_TEST.py", line 21, in <module>
229:     from ignition.math import Vector3d
229: ModuleNotFoundError: No module named 'ignition.math'

https://build.osrfoundation.org/job/ignition_gazebo-ci-pr_any-homebrew-amd64/8052/console

that is unrelated to these changes

[methylDragon]

Ok, I will merge so that we can carry on with the bump. Required CI is green and this is a relatively trivial change.

[osrf-triage]

This pull request has been mentioned on Gazebo Community. There might be relevant details there:

https://community.gazebosim.org/t/new-releases-2022-04-27-fortress-citadel/1389/1