Make fuzzy finder accessible to screen readers
Created by: olafurpg
Previously, screen readers were not able to announce the selected filename when using the fuzzy file finder. This commit adds missing HTML attributes so that screen readers can speak out the selected file path.
Following up from https://github.com/sourcegraph/sourcegraph/pull/21919#issuecomment-859716845 Thank you @felixfbecker for catching the bug!