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
result = self.calculate_retention(request)
        return Response(result)
    @cached_function
    def calculate_retention(self, request: request.Request) -> Dict[str, Any]:
        team = self.team
        data = {}
        if not request.GET.get("date_from"):
            data.update({"date_from": "-11d"})
        filter = RetentionFilter(data=data, request=request, team=self.team)
        base_uri = request.build_absolute_uri("/")
        result = ClickhouseRetention(base_uri=base_uri).run(filter, team)
        return {"result": result}
    
    
    
    
    
    
    
    @action(methods=["GET", "POST"], detail=False)
    def path(self, request: request.Request, *args: Any, **kwargs: Any) -> Response: