CourtListener coverage could be expanded greatly

[konklone]

Right now, the court_opinions adapter limits the courts searched to certain classes of federal courts. I limited it so that I could evaluate how the integration went, before deciding to expand it.

This was a good idea, as it turned out, because CourtListener had a race condition issue that took some time to nail down. But I resolved it with them, and removed the gate that checked for the bug in a5feb66.

So, now that CL integration is stable, dropping the blacklist, or expanding it in stages, would be a simple way to expand Scout's coverage. (Especially valuable are state supreme courts.)