Add validation checks to class constructors

[K20shores]

• Rate constants
• Rosenbrock solver
• Process

alternatively, add a function that checks if the Rosenbrock solver is configured with enough information to run. For example, that each rate constant has a valid pointer

[K20shores]

This doesn't fail:

  Process r4 = Process::create()
                   .reactants({ c, c })
                   .products({ yields(e, 1) })
                   .rate_constant(SurfaceRateConstant({ .label_ = "c", .species_ = c, .reaction_probability_ = 0.90 }))
                   .phase(gas_phase);

it should because the surface rate constant can only react away 1 mole