refactor ordering of dim template arguments

Since we rarely have matrix-valued functions, it makes more sense to have

template <class AssemblyGridView,
          size_t s_r = 1,
          size_t r_r = s_r,
          size_t s_rC = 1,
          size_t r_rC = s_rC,
          class F = double,
          class SGV = AssemblyGridView,
          class RGV = AssemblyGridView>
class BilinearForm

as template arguments than (as we currently have)

template <class AssemblyGridView,
          size_t s_r = 1,
          size_t s_rC = 1,
          size_t r_r = s_r,
          size_t r_rC = s_rC,
          class F = double,
          class SGV = AssemblyGridView,
          class RGV = AssemblyGridView>
class BilinearForm

This applies to all places with similar arguments.