@rpezzi ? Could you please approve this. @frmanso : I slight more verbose commit message with few more explanations of why this is done would be appreciated.

It is a little difficult to see what has really changed, since there are many things from clang-format modifications. Please try to avoid this. In principle it has to do with moving the material definitions there where they belong, since some of them were wrongly put in other files.

Thanks for the commit Sandro. 28 days needed for this small commit with all green lights and no comments, presented in MFT meeting, it's difficult to understand this so long delay.