Explicitly ignore 1xx responses

[annevk]

Per HTTP the reply to a request is a sequence of responses. We only handle (and expose) the last of those, but are not very explicit about it.

We should fix that as it makes it clearer what the interaction actually is and easier to talk about extensions around 1xx.

[annevk]

101 should be returned however as otherwise WebSocket breaks...

[cassepipe]

So this means that if I have a backend returning 100 from a fetch request the client made, the request will never complete ?

[annevk]

If that is all you return, yes. That would also be in line with the RFCs.