Display connection rejection errors passed to client

[raymyers]

End-user friendly description of the problem this fixes or functionality that this introduces

• Include this change in the Release Notes. If checked, you must provide an end-user friendly description for your change below

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Give a summary of what the PR does, explaining any non-trivial design decisions

In our backend, we raise ConnectionRefusedError. SocketIO passes that message to the client. The client did ignore it but will now display it to the user.

Open questions

We may need to find a way to prevent the same message from displaying repeatedly, if so we can handle this more generally later, e.g. by showing repeated messages with a count.

This does not give the message an id, which appears to be for i18n. However some of the other uses seem to omit id as well so the type has been updated to more accurately reflect this as an optional field.

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Link of any specific issues this addresses

ALL-959

[raymyers]

To trigger this on demand, your can add this listen_socket.py in connect(). Potentially we could use flags to enable faults like this in integration tests.

    import random
    if random.random() < 0.2:
        raise ConnectionRefusedError('Dev injected random failure')

[raymyers]

I think e2e ran successfully before, it might just need to rerun

[amanape]

Yes it happens sometimes

[raymyers]

Yes it happens sometimes

Does it just retry on its own or is there something we press to restart it?

[amanape]

Click on the failed job -> scroll up and you'll see something like "Re-run jobs" on the top right. Click it and the "Re-run failed jobs only" option.

I've already done it by the time you've commented 😃