## Is your feature request related to a problem?

When trying to create a filter for a query, value autocompletes are case sensitive. This throws up weird behaviors. 

E.g, with the country name filter entering 'f' as the first letter autocompletes to 'Africa' (and, for some reason, the Isle of Man) and 'France is not listed as an option. Entering 'F' autocompletes to France. 

## Describe the solution you'd like

Not case sensitive results, or else better filtering. Africa shouldn't come up if I only enter 'f'. 

## Describe alternatives you've considered



## Additional context


<img width="886" alt="Screenshot 2022-01-12 at 13 40 00" src="https://user-images.githubusercontent.com/84011561/149151022-6648bc51-c0ff-4116-8611-cb64e88e9483.png">

<img width="887" alt="Screenshot 2022-01-12 at 13 40 11" src="https://user-images.githubusercontent.com/84011561/149151048-86098606-551b-4757-b133-f80b739c4974.png">


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

posthog/api/event.py
import json
import urllib
from datetime import datetime, timedelta
from typing import Any, Dict, List, Optional, Union, cast
from django.db.models import Prefetch, QuerySet
from django.db.models.query_utils import Q
from django.utils import timezone
from django.utils.timezone import now
from rest_framework import mixins, request, response, serializers, viewsets
from rest_framework.decorators import action
from rest_framework.exceptions import ValidationError
from rest_framework.pagination import LimitOffsetPagination
from rest_framework.permissions import IsAuthenticated
from rest_framework.settings import api_settings
from rest_framework_csv import renderers as csvrenderers
from posthog.api.routing import StructuredViewSetMixin
from posthog.models import Element, ElementGroup, Event, Filter, Person, PersonDistinctId
from posthog.models.action import Action
from posthog.models.event import EventManager
from posthog.permissions import ProjectMembershipNecessaryPermissions, TeamMemberAccessPermission
from posthog.queries.base import properties_to_Q
from posthog.utils import convert_property_value, flatten, relative_date_parse
class ElementSerializer(serializers.ModelSerializer):