Create a validation pipeline to check ROOT schema evolution is maintained.

When we generate a new official release, we should create a ROOT file that contains a dummy object of each class from each library. Then, any future pipeline should try to read the ROOT official release generated file and check that it is possible to open it without any warnings. Typical ROOT warnings when ClassDef version is not increased.

This will assure backwards compatibility.

We need a macro/code that lists all metadata classes (including processes), creates an instance of each, writes the default initialisation to disk, and places it to a common place. We do that for each official release.

Then, simply try to open each of the files available at common place, where each file corresponds to a previous official release.

@lobis @rest-for-physics/core_dev

Start by locating the framework's metadata classes, including process classes, and the existing release or pipeline entry points. Define how a macro or other code should create default instances, write one ROOT file per official release, and reopen prior release files without warnings; done means the validation covers all available release files and detects schema-evolution warnings.