Site await site.start() but doesn't await a future when to stop... I

[llacroix]

Describe the bug
It's a bug because the endpoint only block because the docker endpoint blocks too. In reality the server endpoint returns from await site.start().

Additional context

We should use a future to await. This way we can trigger a stop on the web endpoint, properly cleanup and also stop the docker endpoint. It's also possible we can completely test the main after those changes are made. Currently the run_until prevent testing completely the main as there's no way to finish the jobs. With that in mind, we can run_until and trigger an even that will trigger a shutdown. For example, checking for SIGTERM signal or SIGHUP. When the signal handler is called even from the tests, it will be possible to increase the code coverage in theory.