search: make doResults construct text search args (take 2)
Created by: rvantonder
After being reverted, this brings back https://github.com/sourcegraph/sourcegraph/pull/26249 without the OOM bug mentioned in https://github.com/sourcegraph/sourcegraph/pull/26249#discussion_r732357432 (I'm pretty sure this is a correct fix). I've tried to see if I could see the memory consumption locally but it's hard to gauge. I'll monitor changes closely after deploy because clearly this code is a bit sensitive.
See inline comments.