Added storm-pars linker dependency to storm-dft

[volkm]

storm-dft/transformations/DftInstantiator.cpp depends on storm-pars/utility/parametric.h

[sjunges]

Depending on a header should not be a reason to link with a library?

[volkm]

That is true and for me, compilation worked before as well.
There was a report on some build issues by a student which lead to this change. We could keep it open for now and wait whether others have the same issue.