Major refactoring: added the "State" property to Trade (instead of a bunch of unrelated flags). "Winner" is now an IApplicationUser. Added "TradeFeedback" to keep track of pending feedback (HasReceivedFeedbackFromOwner/Winner helper properties).
Users received a message when a feedback is left.
Users other than the owner & the winner cannot leave a feedback (unauthorized).
Users can leave only 1 feedback for each completed trade.
Added unit tests project DayZTradeCenter.Tests.Unit
Added DayZTradeCenterDbContext; added migration "added items".
Added project DayZTradeCenter.Modules that sets up a sql repository for the Items; added weapons items to the db.