Added notification action to mark messages read

Fixes #126

app/src/main/java/eu/faircode/email/DaoMessage.java

@@ -167,6 +167,12 @@ public interface DaoMessage {
             " AND NOT ui_found" /* keep found messages */)
     List<Long> getUids(long folder, long received);
 
+    @Query("SELECT message.* FROM message" +
+            " JOIN folder ON folder.id = message.folder" +
+            " WHERE NOT message.ui_seen" +
+            " AND folder.unified")
+    List<EntityMessage> getUnseenUnifiedMessages();
+
     @Insert
     long insertMessage(EntityMessage message);