Allow successive navigation without intermediate rendering

[sv2dev]

There should be a router.render() method that allows navigation without intermediate rendering.
This can solve situations where you want to manipulate the history stack, but don't want to actually render this intermediate step.
Example:

await router.render(async () => {
  router.go(-3); // Same as history.go(-3)
  await router.go("/route1"); // history state pushed
  await router.go("/route2"); // Same here
});
// Render once all navigation steps are done

Alternatives:

router.go(-3, {skipRender: true});
await router.go("/route1", {skipRender: true});
await router.go("/route2", {skipRender: true});
await router.render();