Rename 'state' to 'scope'

src/utility.c

@@ -162,7 +162,7 @@ void ucl_print_obj(struct ucl_object *obj) {
     }
 }
 
-struct ucl_object *ucl_progn(struct ucl_state *state, struct ucl_object *forms) {
+struct ucl_object *ucl_progn(struct ucl_scope *state, struct ucl_object *forms) {
     struct ucl_object *result = NULL;
     FOREACH_LIST(forms, iter, form) {
         result = ucl_evaluate(state, form);