alpha.9 breaks searching in non-latin languages

Searchin in non-latin (cyrillics in my case) returns no results (was working in alpha.8).

@mojavelinux has investigated the issue: line search-result-highlighting.mjs L96 (commit) is failing.

It incorrectly assumes that match always returns an array. But this is a mistake. It should be checking whether the match returns a non-null object.

Also, that search highlighting logic is assuming english only. \w will only match [A-Za-z0-9_].