Route collision between [responseId] and read-only

[SachaG]

http://localhost:3000/en-US/survey/state-of-js/2022/read-only/1 should match the read-only route but it matches the [responseId] one instead, it seems.

[eric-burel]

I've changed the behaviour like so:

• "/state-of-js/2022/outline/1" will point to a read-only + no response survey. I've fixed the types so it's a bit more explicit that throughout the form, you may not have a response
• "/stateof-js/2022/1234/1" will get your response, and display it in read-only mode if the survey is closed

I've kept separated folders, because "outline" slightly differs: it doesn't have a "finish" page for instance.