RFC: optional abicheck path for libqb ABI checks

Hi libqb maintainers,

I looked at the ABI flow in `./check abi `. Would you be open to evaluating `abicheck` (https://github.com/napetrov/abicheck) as an optional parallel path?

The idea is not to replace your current process immediately, but to run both paths for a while and compare outputs on the same version pairs.

If useful, I can contribute a PR that adds an opt-in `abicheck` mode and preserves your current report layout.

Would that be acceptable?