… rejection

Currently the suggestion collectors collect method has no way of signaling back
to the caller whether the matched completion it received was indeed collected.
While this is currenty always the case for the default TopSuggestDocsCollector,
there are implementations that overwrite this with custom collection logic that
also deduplicates based on e.g. docID and/or context. Currently if those
completions are rejected, the calling TopNSearcher has no way of noting these
rejections and might therefore terminate early, missing on completions that
should be returned.

…or rejections