distribute: Distribute energy flows to batteries.
In cvmartin/eflows: Data-driven energy transition

Given a number of factors, the function returns the

1 2	distribute(flow, soc, vol, share = 1, level = 1, active = 1, eff = 1, cap = 0)

`flow`	Energy flow to be exchanged in the following time step. Positive for charge, negative for discharge.
`soc`	Current state of charge.
`vol`	Objective state of charge to be achieved.
`share`	Double, indicating the priority to share the energy flow.
`level`	Integer, expressing the priority to be resolved, starting with the highest.
`active`	boolean, expressing whether the battery should be considered
`eff`	Efiiciency of the energy flow.
`cap`	Maximum energy that can be exchanged witht the battery