Streaming search: "check your internet" message on long-running searches

Created by: lguychard

On some long-running searches like foo bar count:10000 timeout:20s I get an error state in the "Skipped" UI element, with the following message:

But my internet is working fine.

Inspecting the stream SSE request, it shows up as 200 with 4 events (matches, progress, matches, progress):

cc @limitedmage