Logs: Fix known issues or exclude them from the main view

When supporting a system you frequently need a view of the aggregated errors that the system is generating.
However there will sometimes be an error in the logs that you just can’t fix or it is not worth fixing yet.

Exclude these from the main view as they will mask out real problems further down the frequency table.

This is especially important if you are trying to fix the most frequent error each week, If the same error is always there no progress will be made.