* Add PropFilterModal (only UI)

* small variable refactor

* allow selecting prop value filter type

* allow selecting only one prop_key

* allow selecting many prop_values only when prop_key selected

* handle submitting filter

* get applied filters from query + remove option

* change prop filter label format

* support member and not_member filter types for pageview props

* show (none) value in filter suggestions

* refactor zip_results/4 and remove unused code

* fix displaying (none) values in goals section prop breakdown

* remove unnecessary functionality

* fix bug: returning prop names for goal :member filter

* fix bug: submitting regular filter modal with Enter key

* bugfix: disallow opening prop filter modal when feature flag disabled

* mix format

* break selected combobox values into multiple lines

* fix useEffect behavior for focusing on prop_key field

* support submitting prop filter with Enter key

* refactor getFormState in PropFilterModal

* separate fetchPropKey and fetchPropValue functions

* Allow querying props for pageview goals

* Make the internal props API only return a list of props (not map)
* Separate function for fetching all props in Stats API goal breakdown (this returns a map as before)

* ditch state for keeping search bar visible

* group by event_name in db query