Fix symbolic parameter substitution

[jackvreeken]

Relevant with something like

    def compiler_options(self):
        options = super().compiler_options()
        options["replace_parameter_expressions"] = False
        options["resolve_parameter_values"] = False
        return options

• Test with symbolic parameters in model, e.g.

parameter Real a = 2.0;
parameter Real b = 10.0;
parameter Real ub = a * b;

Real x(max=ub);