Interfaces: Rename PDFAttachments to PDFEmbeds, also throw zugferd exception when zugferd-invoice.xml could not be parsed

GUIs.Test.ZUGFeRDTest/Form1.vb

@@ -167,7 +167,7 @@ Public Class Form1
     End Sub
 
     Private Sub Button7_Click(sender As Object, e As EventArgs) Handles Button7.Click
-        Dim oExtractor = New PDFAttachments(_logConfig)
+        Dim oExtractor = New PDFEmbeds(_logConfig)
         Dim oResult = OpenFileDialog1.ShowDialog()
 
         If oResult = DialogResult.OK Then