Improve handling of unselecting languanges in composer language menu (#1093)

* allow toggling off/on multiple from main composer lang menu

* fix dropdown styles for long labels

* udpate model to use new string field

* update language UI

* save langs to history on submit

* remove edit

* clean up use new fields

* default to deviceLocales

* fix default valu

* feedback

* use radio icon

src/view/com/util/forms/DropdownButton.tsx

@@ -319,9 +319,12 @@ const styles = StyleSheet.create({
   icon: {
     marginLeft: 2,
     marginRight: 8,
+    flexShrink: 0,
   },
   label: {
     fontSize: 18,
+    flexShrink: 1,
+    flexGrow: 1,
   },
   separator: {
     borderTopWidth: 1,