The BinaryMetadataWorkListener is not triggering the work after a document update

In the BinaryMetadataWorkListener we check only the document context data for the 'asyncExecute' flag, instead we should be checking the event properties since the context data of the document is actually copied on the event context properties on saveDocument().

To reproduce:

• disable the BinaryMetadataSyncListener as we dont need the picture metadata to be extracted synchronously
• make sure the flag 'asyncExecute' is set on the document context as its being checked by the listener