[FEATURE] sales logging

[NoFoolLikeOne]

Is your feature request related to a problem? Please describe.

Occasionally we have events where we want to log commodity sales.

Describe the solution you'd like

A white list lookup for systems we want to log at startup.

Then after startup we can use the whitelist to log the data.

Describe alternatives you've considered

Additional context

[NoFoolLikeOne]

{ "timestamp":"2019-04-13T09:41:27Z", "event":"MarketSell", "MarketID":128819860, "Type":"scientificsamples", "Type_Localised":"Scientific Samples", "Count":1, "SellPrice":5795, "TotalSale":5795, "AvgPricePaid":0 }