Gets a System.Collections.Generic.Dictionary containing additional embedded data contained in a PDF document. Supported formats are specified through the EmbeddedDataFormat enumeration. Each entry in the dictionary is a key-value pair, the key is an EmbeddedDataFormat enumeration value and the value is a string with the data in the specified format. This Dictionary is filled only, if the PDFImportSettings property specifies the LoadEmbeddedData setting.