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
"""
        When loading an insight for a dashboard pass a `from_dashboard` query parameter containing the dashboard ID
        e.g. `"/api/projects/{team_id}/insights/{insight_id}?from_dashboard={dashboard_id}"`
        Insights can be added to more than one dashboard, this allows the insight to be loaded in the correct context.
        Using the correct cache and enriching the response with dashboard specific config (e.g. layouts or colors)
        """
        instance = self.get_object()
        serializer_context = self.get_serializer_context()
        dashboard_tile: Optional[DashboardTile] = None
        dashboard_id = request.query_params.get("from_dashboard", None)
        if dashboard_id is not None:
            dashboard_tile = (
                DashboardTile.objects.filter(dashboard__id=dashboard_id, insight__id=instance.id)
                .select_related("dashboard")
                .first()
            )
        if dashboard_tile is not None:
            
            serializer_context.update({"dashboard": dashboard_tile.dashboard})
        serialized_data = self.get_serializer(instance, context=serializer_context).data
        if dashboard_tile is not None:
            serialized_data["color"] = dashboard_tile.color
            layouts = dashboard_tile.layouts
            
            if isinstance(layouts, str):
                layouts = json.loads(layouts)
            serialized_data["layouts"] = layouts
        return Response(serialized_data)