Sentry Issue: [POSTHOG-821](https://sentry.io/organizations/posthog/issues/3707400683/?referrer=github_integration)

Sentry is reporting that when listing session recordings loading persons is n+1

Looking at how the query works 

we 
* load person distinct ids for recordings in the list
* load the persons that have those distinct ids
* create a fict of distinct id to person
* for each of the recordings
    * look up the  person in the dict and pass them to a `PersonSerializer`
    * that looks up the person's distinct ids while choosing Person's `name`
    * (maybe only when there's no email) in order to determine the first distinct id for the person
    
 That final lookup of distinct ids is (**I think**) where the n plus 1 problem is. 
 
 For each person one at a time we go to the DB and get their distinct ids
 
 There's no foreign key from `Person` to `PersonDistinctId` so we can't utilise `select_related` here. 
 
 _maybe_ we can if we use a list serializer for Persons and then combine the two lists
 
 Some of the reports suggest 50% of the time generating the list is spent loading persons
posthog/api/test/test_session_recordings.py
self.assertIsNone(response_data["result"]["next"])
                else:
                    self.assertIsNotNone(response_data["result"]["next"])
                next_url = response_data["result"]["next"]
    def test_get_metadata_for_chunked_session_recording(self):
        with freeze_time("2020-09-13T12:26:40.000Z"):
            p = Person.objects.create(
                team=self.team, distinct_ids=["d1"], properties={"$some_prop": "something", "email": "bob@bob.com"}
            )
            chunked_session_id = "chunked_session_id"
            num_chunks = 60
            snapshots_per_chunk = 2
            for index in range(num_chunks):
                self.create_chunked_snapshots(
                    snapshots_per_chunk, "d1", chunked_session_id, now() + relativedelta(minutes=index)
                )
            response = self.client.get(f"/api/projects/{self.team.id}/session_recordings/{chunked_session_id}")
            response_data = response.json()
            self.assertEqual(response_data["result"]["person"]["id"], p.pk)
            self.assertEqual(
                response_data["result"]["session_recording"]["start_and_end_times_by_window_id"],
                {
                    "": {
                        "is_active": False,
                        "window_id": "",
                        "start_time": now().replace(tzinfo=timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ"),
                        "end_time": (
                            now() + relativedelta(minutes=num_chunks - 1, seconds=snapshots_per_chunk - 1)
                        ).strftime("%Y-%m-%dT%H:%M:%SZ"),
                    }