List inequal fields of nodes with same name

[mkuhring]

When nodes from separate rows get the same unique_name, they are assumed to be part of splitting or pooling and to have the same annotation. In case of unequal annotations, an exception is thrown listing both nodes completely. Instead the message should be limited to identifying information (type, unique_name, name) and the differences in annotation, for instance:

ISAtab parsing failed: Found materials with same name but different annotation:
  material 1: type='Source Name', unique_name='S0-source-patientX', name='patientX'
  material 2: type='Source Name', unique_name='S0-source-patientX', name='patientX'
  differences: Characteristics[Gender]: "male" != "female"