Pick up instruments from portfolio after restart

[somnoynadno]

Currently, workers can only trade with instruments that they buy by themselves. So, if worker has an asset and willing to sell it, after restart that assets will be forgotten and remains in portfolio before manual user action.

We can check assets in portfolio before start trading: if we have some, it's better to supervise them first or set a proper "stop-loss" / "take-profit" order before exit.