Add "Who can reply" controls [WIP] (#1954)

* Add threadgating

* UI improvements

* More ui work

* Remove comment

* Tweak colors

* Add missing keys

* Tweak sizing

* Only show composer option on non-reply

* Flex wrap fix

* Move the threadgate control to the top of the composer

src/view/com/composer/text-input/web/EmojiPicker.web.tsx

@@ -98,7 +98,8 @@ const styles = StyleSheet.create({
     backgroundColor: 'transparent',
     border: 'none',
     paddingTop: 4,
-    paddingHorizontal: 10,
+    paddingLeft: 12,
+    paddingRight: 12,
     cursor: 'pointer',
   },
   picker: {