Add GetBytes() extension to barcodes

DEVSIX-1845

Author: pavel-alay

itext/itext.barcodes/itext/barcodes/BarcodesExtensions.cs

@@ -78,6 +78,10 @@ public static TValue Put<TKey, TValue>(this IDictionary<TKey, TValue> col, TKey
             col[key] = value;
             return oldVal;
         }
+        
+        public static byte[] GetBytes(this String str) {
+            return System.Text.Encoding.UTF8.GetBytes(str);
+        }
 
         public static Assembly GetAssembly(this Type type) {
 #if !NETSTANDARD1_6