Allow to accept multiple orders in parallel

[moonlight200]

Allow a user to accept multiple orders at once, e.g. if two clients are very close together.

[bene99]

the methode getMyOrders() returns now the orders of a person

[Basler182]

Maybe we should simply add a second List with active Orders? Currently, we jump directly to the current step of the active order. We could adapt it to jump to the current step of a order after someone selected one of the active orders in the list. So it would be easy to do multiple orders at once.

[moonlight200]

We could also add multiple notifications so that the user can easily jump to one particular order. Maybe group them like multiple chat notifications in an instant messaging app.