This strategy is responsible for deciding at which stage in the order process stock will be allocated.
This is configured via the orderOptions.stockAllocationStrategy property of
your VendureConfig.
InjectableStrategy(ctx: RequestContext, fromState: OrderState, toState: OrderState, order: Order) => boolean | Promise<boolean>This method is called whenever an Order transitions from one state to another.
If it resolves to true, then stock will be allocated for this order.
It may be called more than once for the same transition, because the transition guard also asks whether the allocation will happen now. Implementations must return the same result each time for the same arguments, and must be free of side effects.