insights: test capture group insights with multiline matches

Created by: leonore

We should be able to start using multiline matches in capture group insights: https://github.com/sourcegraph/sourcegraph/pull/39113#event-7030954029

we should test this does work with insights, and doesn't break (I'm pretty sure it used to time out every time in the query runner)

example multiline match: https://sourcegraph.com/github.com/renovatebot/renovate/-/blob/lib/modules/manager/terraform/__fixtures__/modules.tf