At the moment we are manually cancelling letters for people when they
ask us to. Once’s we’ve done this there is no indication that it’s
happened except for the date going red on the list of letters.
This commit adds some error messaging and styling to show when a letter
is cancelled.
Letting people cancel their own letters will be a future enhancement.
Since we’ve removed the table of notifications from the single
notification page there’s no way of knowing the status of a
notification.
This re-adds it in a way that’s similar to how it looks on inbound
messages.
