Get rid of PdfSignatureAppearance class

DEVSIX-8550

Author: AnhelinaM

simple/src/test/java/com/itextpdf/signingexamples/jcajce/CreateSignatureAppearance.java

@@ -50,7 +50,6 @@
 import com.itextpdf.layout.properties.BackgroundSize;
 import com.itextpdf.signatures.BouncyCastleDigest;
 import com.itextpdf.signatures.IExternalSignature;
-import com.itextpdf.signatures.PdfSignatureAppearance;
 import com.itextpdf.signatures.PdfSigner;
 import com.itextpdf.signatures.PdfSigner.CryptoStandard;
 import com.itextpdf.signatures.PrivateKeySignature;
@@ -521,7 +520,8 @@ public void testMachineReadables() throws IOException, GeneralSecurityException
  }
 
  /**
- * This test illustrates an issue in the {@link PdfSignatureAppearance#setReuseAppearance(boolean) ReuseAppearance}
+ * This test illustrates an issue in the
+ * {@link com.itextpdf.forms.fields.PdfSignatureFormField#setReuseAppearance(boolean) ReuseAppearance}
  * feature of iText: Here the complete normal appearance of the unsigned field is re-used as n0 layer of the signed
  * field. Unfortunately it was forgotten that the original appearance was displayed so that its BBox transformed by
  * its matrix fits into the annotation rectangle. If BBox of the original appearance does not have its lower left