Retry inspector if it tries to load without service data.

Adds a Y.later based retry mechanism for the _inspector in cases where the service inspector should be opened but the services haven't had a chance to load from the environment yet.
Yeah, this is a bit of future proofing.

Right now, the only way you could set up this error condition and then navigate away from it is to click another service icon, so clearing the timer in `_inspector` works. But if we add any other element you can click that's accessible from this error state that causes a navigation elsewhere, we'll end up with an odd bug.

I'll add the comment.