Add trade history and "Undo" feature

You can easily make mistakes with trades in the UI, and it can be hard to see the difference before you take action. It is desirable to store a history of all past trades made, and add an "undo" action that reverse previous trades so you can quickly make a change, see the change in action, and then "undo" that change to go back again.

It might be a good idea to preserve the history of actions for a long time so you can "undo" and then "redo" actions from even days ago.