fix: retain system data on structural_simplify of SDESystem

Author: AayushSabharwal

src/systems/systems.jl

@@ -164,6 +164,7 @@ function __structural_simplify(sys::AbstractSystem, io = nothing; simplify = fal
         return SDESystem(Vector{Equation}(full_equations(ode_sys)), noise_eqs,
             get_iv(ode_sys), unknowns(ode_sys), parameters(ode_sys);
             name = nameof(ode_sys), is_scalar_noise, observed = observed(ode_sys), defaults = defaults(sys),
-            parameter_dependencies = parameter_dependencies(sys))
+            parameter_dependencies = parameter_dependencies(sys),
+            guesses = guesses(sys), initialization_eqs = initialization_equations(sys))
     end
 end