insights: Fix back integration tests so they can run as part of the CI

Created by: CristinaBirkel

Some customers had issues upgrading their single-docker sourcegraph deployments due to the codeinsights-db being included. So the codeinsights-db was removed to fix the issue, and made it so that we can't run integration tests. Here's a link to that issue.

This issue is to find a way to re-introduce the integration tests.