Update PALM4MSA 2020 impl. to allow dynamic output format in proximal operator.

The dynamic format is selected (MatSparse or MatDense) to spare memory (and morover PALM4MSA computation time on CPU).

- use_csr argument/parameter is replaced by factor(s)_format parameter (a value of the new enum FactorsFormat: AllDense, AllSparse, AllDynamic).
- Refactor dynamic proxs in the new module faust_prox_gen (templated to work for both Cpu and GPU2 FDevice).
- Add function project_gen() in Constraint* class that returns a MatGeneric produced by faust_prox_gen module proxs.
- Add function replace() in Faust::TransformHelper class (Cpu and GPU2).