FilterList: Add key value to filter list items

[kellyhutchins]

When updating the filter list via the config panel we need to be able to add/remove filter items from the list. When a new item is added we get the following error:
Uncaught Error: div had a div child added, but there is now more than one. You must add unique key properties to make them distinguishable.

To resolve add a key property to the filter list items