[APP-690] better handling of post languages language filtering (#893)

* add SelectLangBtn

* memoized objects that are created to reduce re-creation on re-render

* add langs when uploading post

* only send the top 3 languages otherwise backend will throw error

* mv ContentLanguagesSettings to folder

* add post languages settings modal and state

* fix typos

* modify feed manip to also check langs label on post

* Fix tests

* Remove log

* Update feed-manip.ts

* Fix syntax errors

* UI tuneups

* Show the currently selected languages in the composer

* fix linting

* Use a bcp-47 matching function

* Fix a duplicate language issue

* Fix web

* Dont include lang in prompt

* Make select language btn an observer

* Keep device languages on top of language selection UIs

* Fix android build settings

* Enforce a max of 3 languages in posts

* Fix tests

* Fix types

---------

Co-authored-by: Paul Frazee <pfrazee@gmail.com>

src/view/com/modals/lang-settings/ConfirmLanguagesButton.tsx

@@ -0,0 +1,52 @@
+import React from 'react'
+import {StyleSheet, Text, View, Pressable} from 'react-native'
+import LinearGradient from 'react-native-linear-gradient'
+import {s, colors, gradients} from 'lib/styles'
+import {isDesktopWeb} from 'platform/detection'
+import {usePalette} from 'lib/hooks/usePalette'
+
+export const ConfirmLanguagesButton = ({
+  onPress,
+  extraText,
+}: {
+  onPress: () => void
+  extraText?: string
+}) => {
+  const pal = usePalette('default')
+  return (
+    <View style={[styles.btnContainer, pal.borderDark]}>
+      <Pressable
+        testID="confirmContentLanguagesBtn"
+        onPress={onPress}
+        accessibilityRole="button"
+        accessibilityLabel="Confirm content language settings"
+        accessibilityHint="">
+        <LinearGradient
+          colors={[gradients.blueLight.start, gradients.blueLight.end]}
+          start={{x: 0, y: 0}}
+          end={{x: 1, y: 1}}
+          style={[styles.btn]}>
+          <Text style={[s.white, s.bold, s.f18]}>Done{extraText}</Text>
+        </LinearGradient>
+      </Pressable>
+    </View>
+  )
+}
+
+const styles = StyleSheet.create({
+  btnContainer: {
+    paddingTop: 10,
+    paddingHorizontal: 10,
+    paddingBottom: isDesktopWeb ? 0 : 40,
+    borderTopWidth: isDesktopWeb ? 0 : 1,
+  },
+  btn: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    justifyContent: 'center',
+    width: '100%',
+    borderRadius: 32,
+    padding: 14,
+    backgroundColor: colors.gray1,
+  },
+})