Revert "search: clean up / refactor search result merging code (#3022)"
Created by: ijt
This reverts commit a08c7063fe8afd87b1581754d07b6b4b86e96d74.
cc @slimsag
This is in response to #3242. @slimsag is saying that a08c7 may have caused the problem by requiring all the results to come back within 100ms, not just partial results as before.