Feature Request - keep track of total profit/loss

[Joeytje50]

Is your feature request related to a problem? Please describe.
It is currently impossible to see the running total of the profit or loss compared to the base price for the products. I assume this is what the 'financial' tab is intended for, but that currently shows nothing whatsoever.

Describe the solution you'd like
For example, if the base price of a beer is 1.50 eur, and it is being sold for 1.00, I would like some counter to go up by 0.5, and show this in the bar interface. It would be best if it is visible in the main interface, and not somewhere hidden such as the Financial interface.

Describe alternatives you've considered
I've just added a tracker to use localStorage in JavaScript to keep track of it for myself now, but the solution I've implemented probably shouldn't be used on the main product, as using the actual database is much more rigid.