[APP-724] Collection of accessibility fixes (#949)

* Fix: include alt text on the web lightbox image

* a11y: Dont read the 'ALT' label

* a11y: remove a wrapper behavior from posts

This appears to have been introduced with the goal of creating meta
actions on posts, but the behavior seems counter-productive. The
accessibility inspector was unable to access individual items within
the post and therefore most content was simply skipped.

There may be a way to support the post actions without losing the
ability to access the inner elements but I couldnt find it. -prf

* a11y: apply alt tags to image wrappers so they get read

* a11y: set Link accessibilityLabel to the title if none set

* a11y: skip the SANDBOX watermark

* a11y: improve post meta to not read UI and give a useful date

* ally: improve post controls

* a11y: add labels to lightbox images on mobile

* fix types

1 files changed, 4 insertions, 1 deletions

diff --git a/src/view/com/util/post-ctrls/RepostButton.tsx b/src/view/com/util/post-ctrls/RepostButton.tsx
index 59f7f6ee1..4338e4c59 100644
--- a/src/view/com/util/post-ctrls/RepostButton.tsx
+++ b/src/view/com/util/post-ctrls/RepostButton.tsx
@@ -4,6 +4,7 @@ import {RepostIcon} from 'lib/icons'
 import {s, colors} from 'lib/styles'
 import {useTheme} from 'lib/ThemeContext'
 import {Text} from '../text/Text'
+import {pluralize} from 'lib/strings/helpers'
 import {useStores} from 'state/index'
 
 const HITSLOP = {top: 5, left: 5, bottom: 5, right: 5}
@@ -49,7 +50,9 @@ export const RepostButton = ({
       onPress={onPressToggleRepostWrapper}
       style={styles.control}
       accessibilityRole="button"
-      accessibilityLabel={isReposted ? 'Undo repost' : 'Repost'}
+      accessibilityLabel={`${
+        isReposted ? 'Undo repost' : 'Repost'
+      } (${repostCount} ${pluralize(repostCount || 0, 'repost')})`}
       accessibilityHint="">
       <RepostIcon
         style={