Example SBOMs for AntUnit, Ivy and Ant

Hi all

AntUnit's master branch as well as the two PRs for Ivy and Ant
I opened https://github.com/apache/ant/pull/233 and
https://github.com/apache/ant-ivy contain "sboms" directories with SBOMs
I created locally by running the respective distribution builds.

The files follow the same naming patterns I used for the CycloneDX
release.

Would be nice if people could have a look before I merged the
branches. The sboms directories will go awy in either case.

While doing this I found a bug and some shortcoming in the CycloneDX
Antlib - and adding Ivy support there will make SBOM creation for things
that rely on Ivy and have many dependencies (Ivy itself, the CycloneDX
and Compress Antlibs) a bit easier, I guess.

Stefan