dnd5e: Revisit filters and filter logic, now that Activities exist

[kgar]

Now that activities are involved, revisit the item filters and filter logic.
Are there additional filter options that would make sense to add to the advanced filter menu?
Are there changes needed to correct any of the filters?

At present, the assumption is that a filter which involves the item's activities should require at least one activity to meet the filter criterion.

For the UI, it would be useful to filter down the inline activities of each item to the relevant results.