Internationalization & localization (#1822)

* install and setup lingui

* setup dynamic locale activation and async loading

* first pass of automated replacement of text messages

* add some more documentaton

* fix nits

* add `es` and `hi`locales for testing purposes

* make accessibilityLabel localized

* compile and extract new messages

* fix merge conflicts

* fix eslint warning

* change instructions from sending email to opening PR

* fix comments

src/view/com/lightbox/ImageViewing/components/ImageDefaultHeader.tsx

@@ -5,10 +5,10 @@
  * LICENSE file in the root directory of this source tree.
  *
  */
-
-import {createHitslop} from 'lib/constants'
 import React from 'react'
+import {createHitslop} from 'lib/constants'
 import {SafeAreaView, Text, TouchableOpacity, StyleSheet} from 'react-native'
+import {t} from '@lingui/macro'
 
 type Props = {
   onRequestClose: () => void
@@ -23,7 +23,7 @@ const ImageDefaultHeader = ({onRequestClose}: Props) => (
       onPress={onRequestClose}
       hitSlop={HIT_SLOP}
       accessibilityRole="button"
-      accessibilityLabel="Close image"
+      accessibilityLabel={t`Close image`}
       accessibilityHint="Closes viewer for header image"
       onAccessibilityEscape={onRequestClose}>
       <Text style={styles.closeText}>✕</Text>