update(codegen_register): add derive(Copy) to register value enum

It must be unit only enum, so Copy isn't so heavy operation

src/generator/codegen_register.rs

@@ -360,6 +360,7 @@ fn generate_custom_values_const_enumdef(
         util::parse_to_ident(&field_name.to_string().to_upper_camel_case()).unwrap();
 
     quote! {
+        #[derive(Clone, Copy)]
         pub enum #value_enum_name {
             #(#variants),*
         }