Code Insights: Fix `hasInsights` api method and therefore smart redirect for the main insight page
Created by: vovakulikov
Closes https://github.com/sourcegraph/sourcegraph/issues/32387
Test plan
- Check that if you have at least one available to you insight you see the dashboard page when you click on the global nav item "Insights"
- Check that you don't have any available insights you should have been redirected to the getting started page
How did we miss this
Prior to this PR, we did rely on the page info object to determine do users have available to their insights or not. It always returns has next page and therefore we always saw redirections to the dashboard page. It has been fixed in this PR https://github.com/sourcegraph/sourcegraph/pull/30086 and now everything works as it should but it broke bad FE logic.