Fix `repo:` filter in linked diff search for search-based live preview insight.
Created by: vovakulikov
Fixes https://github.com/sourcegraph/sourcegraph-search-insights/issues/7
Thanks, @felixfbecker we have a PR with the same fix in the search-based extension codebase about link generation PR https://github.com/sourcegraph/sourcegraph-search-insights/pull/11. This PR adds the same changes and fixes in the live preview creation UI for search-based insight.