bound vq_state_up and down #309
Description
vq_state_up and vq_state_down are unbounded variables. A strict bound for vq_state_up could be the demand for each node, but this could potentially lead to infeasible situations. A less strict bound could be the sum of all incoming capacities (plus investable capacities).
It should also be allowed to turn vq_state off for a particular node to reduce variables when the modeller knows that there cannot be infeasibilities.