Store Jacobian buffer as ConstraintSet member or a solver temporary variables to avoid reallocating on every solver call

[boulderdaze]

ConstraintSet::SubtractJacobianTerms allocates jac_buffer (and resizes concentrations for vectorized dense) on every call. This is both a performance hit inside the solver loop and can throw exceptions (bad_alloc), which is especially problematic since Rosenbrock::Solve is marked noexcept. Consider storing these scratch buffers as members of ConstraintSet or solver temporary variables and resizing once during setup.

[boulderdaze]

No longer needed after the refactoring done in #949