[Config] Use cmake-generator-expression to set cxx and c flags

[fredroy]

It allows to differentiate C/C++/CUDA/(maybe other) flags which are passed through dependencies.

Fix compilation problem with

• https://github.com/sofa-framework/sofa/pull/4878 where specific msvc flags are passed to nvcc (and raise errors)

This should be propagated in a potential cleaning of SofaCUDA

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