OpenDSS export of ShortCircuitTest

[temcdrm]

In the current implementation:

• OpenDSS exports the leakageImpedance as X, rather than sqrt(R^2 + X^2).
• OpenDSS exports all of the tested load loss in the first ShortCircuitTest for a transformer. This happens to be okay for 2-winding transformers, but not multi-winding transformers.
• The exported TransformerEndInfo.r reproduces the load loss test results, when converted into TransformerMeshImpedance.r, i.e., TransformerEndInfo.r is not really the DC winding resistance.

CIMHub currently compensates for these errors. For compliance to the CIM, both OpenDSS and CIMHub should have matching fixes.

[temcdrm]

Will be fixed after merging feature/cimext