When exporting data from [an insight](https://app.posthog.com/insights/oVHjTLUD), the action names weren't exported, making the CSV a little hard to follow.

As a user, I'd expect to see the same data in the export as I see in the table in-app.

<img width="1012" alt="image" src="https://user-images.githubusercontent.com/154479/166958828-9b3add76-633b-4f1d-ad2b-cf1ea2888b95.png">

posthog/api/insight.py
model = Insight
        fields = [
            "id",
            "short_id",
            "name",
            "derived_name",
            "filters",
            "filters_hash",
            "order",
            "deleted",
            "dashboards",
            "last_refresh",
            "refreshing",
            "result",
            "created_at",
            "created_by",