cubicweb-seda #13830622 FileName metadata missing in BinaryDataObject [validation pending]

Add FileName metadata in BinaryDataObject.

prioritynormal
typebug
done in0.4.0
load0.000
load left0.000
closed by#78b3929471cb [code gen] Skip URI/filename on Attachment, reintroduce Filename on BinaryDataObject
patch[code gen] Skip URI/filename on Attachment, reintroduce Filename on BinaryDataObject [applied]