[BUG] DSS Linecode normamps and emergamps are not parsed

[hei06j]

The current ratings specified in dss linecode as normamps and emergamps are not passed to the engineering model. It seems that in the create_dss_object function for linecodes, they are not considered.

Similar to creating objects for wiredata, adding the following lines should be helpful.

normamps = :normamps ∈ raw_fields ? linecode.normamps : :emergamps ∈ raw_fields ? linecode.emergamps / 1.5 : 400.0
emergamps = :emergamps ∈ raw_fields ? linecode.emergamps : :normamps ∈ raw_fields ? linecode.normamps * 1.5 : 600.0

linecode.normamps = normamps
linecode.emergamps = emergamps