fix payment redis final cleanout issue - possible double spending

There could be situation when we send payments using sendmany command but something happened with redis at the same time so no finalRedisCommands will be executed and next time when redis became alive again we will calculate (same) payments again and will pay them one more time. I think of some kind of checkpoint that must be cleared when everything is completed successfully. Also I'm not sure if we can blindly push this commands once redis is alive even if we stored them somehow. You can see my approach to this below.