Allow intentional unfixed integrity check failures to be recorded as such

[llewelld]

User story: "As someone performing cost recovery, it would be useful if previously reviewed integrity checks that are to be left as they are, could be filtered out, so that I don't need to reconsider them during future integrity checks."

The cost-recovery integrity checks currently generate a large number of false positives.

Once something has been checked, but a decision has been made that it doesn't need any changes being made as a result, it would be convenient if it could be marked in the database as such so that it can be filtered out of future integrity checks.