Event looks like registered for though on waiting list

One-sentence description

When on the waiting list for an event, it still looks like you are registered for that event.

Current behaviour / Reproducing the bug

In the calendar stream, the event does appear in your calendar
Cancelling your registration does show the warning that you have to pay a fine, if after the unregistration deadline
In the event overview calendar, the dot in front of the event is colored as if you are registered.

Expected behaviour

Do not appear in the calendar stream
Do not show a message that you cannot unregister without having to pay a fine, but something different more fit to the situation
In the event overview, show some other, pending-ish, colored dot.

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