S13nServiceWorker: make sure the worker is started when ControllerServiceWorker interface ptr is queried or sent by/to the clients.

Currently clients (are going to) have two ways to get the interface ptr to ControllerServiceWorker:

1. Clients can call SWContainerHost::GetControllerServiceWorker() to get the interface ptr. The method is implemented by SWProviderHost in the browser process, and clients usually call it via ControllerServiceWorkerConnector (during subresource loading).

2. Clients can get a new controller ptr when the browser calls SWContainer::SetController() after https://chromium-review.googlesource.com/c/chromium/src/+/742961 lands. The method is called by SWProviderHost in the browser process, and implemented by SWProviderContext in the renderer.

In both cases we should make sure the service worker is running or is starting up, so that the interface ptr is going to work (or connection error happens if the request is dropped).