## Is your feature request related to a problem?

Currently the funnel time to convert query (added in #4947) only allows measuring time it took to a specific step from the one immediately preceding it. However it'd be useful to also bin by the _total_ time to convert – how long it took to complete the funnel (reach the last step) from entering it (reaching the first step).

## Describe the solution you'd like

Right now `ClickhouseFunnelTimeToConvert` uses only `Filter.funnel_to_step`. It should also be able to work with `Filter.funnel_from_step`. If `funnel_from_step` is `0` and `funnel_to_step` is `len(steps)-1`, that'd be the total time to convert.

#### *Thank you* for your feature request – we love each and every one!

ee/clickhouse/queries/funnels/test/test_funnel_time_to_convert.py
maxDiff = None
    def test_auto_bin_count(self):
        _create_person(distinct_ids=["user a"], team=self.team)
        _create_person(distinct_ids=["user b"], team=self.team)
        _create_person(distinct_ids=["user c"], team=self.team)
        _create_event(event="step one", distinct_id="user a", team=self.team, timestamp="2021-06-08 18:00:00")
        _create_event(event="step two", distinct_id="user a", team=self.team, timestamp="2021-06-08 19:00:00")
        
        _create_event(event="step three", distinct_id="user a", team=self.team, timestamp="2021-06-08 21:00:00")
        _create_event(event="step one", distinct_id="user b", team=self.team, timestamp="2021-06-09 13:00:00")
        _create_event(event="step two", distinct_id="user b", team=self.team, timestamp="2021-06-09 13:37:00")
        
        _create_event(event="step one", distinct_id="user c", team=self.team, timestamp="2021-06-11 07:00:00")
        _create_event(event="step two", distinct_id="user c", team=self.team, timestamp="2021-06-12 06:00:00")
        
        filter = Filter(
            data={
                "insight": INSIGHT_FUNNELS,
                "interval": "day",
                "date_from": "2021-06-07 00:00:00",
                "date_to": "2021-06-13 23:59:59",
                "funnel_to_step": 1,
                "funnel_window_days": 7,
                "events": [
                    {"id": "step one", "order": 0},
                    {"id": "step two", "order": 1},
                    {"id": "step three", "order": 2},
                ],
            }