UI: Add 'Save' and 'Discard' to localization text

obs/data/locale/en-US.ini

@@ -10,6 +10,8 @@ Region="United States"
 OK="OK"
 Apply="Apply"
 Cancel="Cancel"
+Save="Save"
+Discard="Discard"
 Yes="Yes"
 No="No"
 Add="Add"