Filter search_result_paths for workspaces
Created by: eseliger
If we decide to adopt this, we need to port this fix to src-cli as well. For details, see the ticket.
For the src-cli PR that does the same change to the local resolution algorithm see here: https://github.com/sourcegraph/src-cli/pull/779 (Warning it might be boring to read)
Closes https://github.com/sourcegraph/sourcegraph/issues/36620
Test plan
Wrote a test for this, and manually verified that the spec from the ticket works correctly now.
