Add fulltext search for posts and profiles (closes #340) (#342)

* Refactor mobile search screen

* Remove 'staleness' fetch trigger on search

* Implement a temporary fulltext search solution

* Add missing key from profile search result

* A few UI & UX improvements to the search suggestions

* Update web search suggestions

* Implement search in web build

src/view/com/util/UserBanner.tsx

@@ -1,6 +1,5 @@
 import React from 'react'
 import {StyleSheet, View} from 'react-native'
-import Svg, {Rect} from 'react-native-svg'
 import {FontAwesomeIcon} from '@fortawesome/react-native-fontawesome'
 import {IconProp} from '@fortawesome/fontawesome-svg-core'
 import Image from 'view/com/util/images/Image'