Generalize efficiency setting for storage models

[genevievestarke]

Generalize efficiency setting for storage models

We currently allow either roundtrip_efficiency or charge_efficiency and discharge_efficiency parameters as inputs to the pyomo storage controller. We should generalize this to allow for the definition of all possible two-out-of-three combinations.

Additionally, we should only allow 2 out of 3 to be defined to prevent the efficiency from being over-constrained.

Proposed solution

Alternatives considered

Additional context