Remove major version from package name

[scpeters]

🎉 New feature

Part of gazebo-tooling/release-tools#1244.

Summary

This removes the major version from the package
name in the following places:

• cmake project name and corresponding find_package calls in examples
• package.xml name

This does not require any downstream changes, because this version of the package is not yet used in Jetty.

Test it

1. Build and install this branch.
2. Build cmake examples.

Checklist

• Signed all commits for DCO
• 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)
• 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.