Enable usage of transformation system with RucioFileCatalog

[maxnoe]

This is currently not possible as the transformation system calls getMetadataFields which is not implemented for the RucioFileCatalog.

src/DIRAC/TransformationSystem/DB/TransformationDB.py
1708:        res = catalog.getMetadataFields()

As commented in #8329, it's also not really possible to implement as is, as rucio doesn't have a fixed metadata schema.

[arrabito]

@maxnoe I would like to mention that it's still possible to enable the TS, i.e. using the InputDataAgent instead of the TSCatalog interface. In this case, that method is not used. See section 8.4.2.2: https://dirac.diracgrid.org/en/latest/AdministratorGuide/Systems/Transformation/index.html This is also the most standard way to use the TS, as done in LHCb. In CTAO we were initially using the TSCatalog interface ('pushing mode') but then reverted back to using the InputDataAgent ('polling mode') as there were scalability issues with the TSCatalog interface method.