Rollup merge of #92127 - GuillaumeGomez:search-results-duplicate-removal, r=jsha

Move duplicates removal when generating results instead of when displaying them

Currently, we store 200 results per tab and then display them. However, it was possible to have duplicates which is why we have this check. However, instead of doing it when displaying the results, it's much better instead to do it even before to simplify the display part a bit.

r? `@jsha`