- Adds metadata writing capability through new `MetadataMode` flag and `writeMetadata` method
- Exports string metadata as STEP `property_definition` entities linked to product definitions
- Integrates metadata writing into the main transfer workflow alongside existing property writing
Product attributes metadata for step files is now handled during import.
Attribute ReadProductMetadata is added to DESTEP_Parameters.
Method STEPCAFControl_Reader::ReadMetadata() is partially refactored.
Metadata tests for STEP are updated with new data.
Metadata tests for GLTF are updated with new data (since original
metadata in those tests is acquired from STEP files).
