Not able to add IfcClassification metadtata for multiple classifications

When multiple classifications are added, for instance by creating a parameter `ClassificationCode(2)`, it is not possible, or not clear, how to add extra IfcClassification attributes to it.

Start by reproducing the issue with a parameter named ClassificationCode(2) and multiple classifications. Trace how IfcClassification metadata is assigned for repeated classifications, then define and verify a way to set the extra attributes for each classification; no source file or test is identified in the issue.

Written by the indexing model from the issue text.