Add function that replaces new hydraulic connection expressions in ddck-files with their default value

[martin-neugebauer]

As a user, I would like pytrnsys to work as before in spite of changes to ddck-files in light of the automatic ddck generation capabilities to be implemented in pytrnsys_gui. For this we need a function to be called from pytrnsys\pytrnsys\trnsys_util\buildTrnsysDeck.py that can handle expressions like @temp(portName, defaultName).