Search backend: Rename `run.RepoSearch` to `run.RepoSearchJob`
Created by: tbliu98
Stacked on https://github.com/sourcegraph/sourcegraph/pull/34865 Related to #34009 (closed)
Because run.RepoSearch
implements job.Job
, renaming run.RepoSearch
to run.RepoSearchJob
for clarity when reading the code and looking at traces.
Test plan
Semantics-preserving.