Implement GridAPPSD-CIM queries for power flow objects

[AAndersn]

Implement initial set of queries needed by App Toolbox services

• [x] ACLineSegment: phase, bus1, bus2
• [x] EnergyConsumer: phase, p, q
• [x] PowerTransformer (including both tank and tankless) : phase, bus1, bus2
• [x] PowerElectronicsConnection : bus, phase, p, q, ratedS
• [x] LoadBreakSwitch: phase, bus1, bus2

Buses requires Terminals query as well.

[poorva1209]

Working on examples.