Sum/Avg/Min/Max of event property is inconvenient to use

[macobo]

Bug description

If you have many event properties, using sum/avg/min/max of event property becomes hell to use.

Expected behavior

Using a text input with autocomplete/suggestions

How to reproduce

1. Send an event with 200 numeric properties to posthog
2. Try to analyze it (e.g. sum one of them

Environment

• Both

Additional context

Ideally only properties actually only on that event would get suggested - currently all properties are.

Note that ideally we should be able to input any property there - not just whitelisted ones.

Also $-prefixed keys are not included instead of using same logic as events does (using PropertyKeyInfo)

Came up during #2560

Thank you for your bug report – we love squashing them!

[timgl]

For future, definitely worth adding the Good First Issue label to help people discover