BASE: Maps still contain duplicates

[pkraker]

Currently, we deduplicate BASE search results on the fly on the basis of publication titles. This is fast and works very well. But as we retrieve a maximum of 125 items, we do not deduplicate items any more once we have boiled it down to 100 items. This means that there are still duplicates in maps with more than 25 duplicates in the original result set.