Migrate some IGNITION_* macros

[scpeters]

🦟 Bug fix

Part of gazebo-tooling/release-tools#698

Summary

The IGNITION_* macros from the autogenerated Export.hh have been migrated to support GZ_* as well as of gazebosim/gz-cmake#249, so the GZ_UTILS_VISIBLE macro is now being used (97a1cfa). This also tick-tocks most of the macros in config.hh.in (notably not the *_BUILD_TYPE_* macros, which are problematic) and migrates to GZ_UTILS_VERSION_NAMESPACE where relevant.

Checklist

• 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.

[chapulina]

LGTM, I guess there's no way to trigger a warning when the IGNITION_ versions are used, right? It's more of a slient-tick and then tock, but I guess that's what we can do.

I believe this is backportable to Citadel and Fortress if we want to reduce the diff between the branches. I don't think we should do that now, we may have time for it after feature freeze.

[scpeters]

LGTM, I guess there's no way to trigger a warning when the IGNITION_ versions are used, right? It's more of a slient-tick and then tock, but I guess that's what we can do.

once you mentioned that, it occurred to me that we could move the IGNITION_* macros to ignition/utils/config.hh, so I did so in 06f7b94

how does that look?