Fix web links resolving for RandomAccessSourceFactory

Anything like this didn't work properly (e.g. for image data creation):
`https://www.google.by/images/branding/googlelogo/2x/googlelogo_color_272x92dp.png`.

Author: yulian-gaponenko

itext.tests/itext.layout.tests/itext/layout/NetWorkPathTest.cs

@@ -40,44 +40,55 @@ source product.
     For more information, please contact iText Software Corp. at this
     address: [email protected]
  */
+
 using System;
-using System.Collections.Generic;
 using System.Globalization;
-using System.Linq;
-using System.Text;
 using System.Threading;
 using iText.IO.Image;
+using iText.Kernel.Pdf;
 using iText.Layout.Element;
+using iText.Test;
+using NUnit.Framework;
 
-namespace iText.Layout
-{
+namespace iText.Layout {
     // This test is present only in c#
     // Also this test in only for windows OS 
-    class NetWorkPathTest
-    {
+    public class NetWorkPathTest : ExtendedITextTest {
+        
         [NUnit.Framework.Test]
-        public virtual void NetworkPathImageTest()
-        {
-            var fullImagePath = @"\\someVeryRandomWords\SomeVeryRandomName.img";
-            string startOfMsg = null;
+        public virtual void NetworkPathImageTest() {
+            String fullImagePath = @"\\someVeryRandomWords\SomeVeryRandomName.img";
+            String startOfMsg = null;
 #if !NETSTANDARD1_6
             Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;
             Thread.CurrentThread.CurrentUICulture = CultureInfo.InvariantCulture;
 #else
             CultureInfo.CurrentCulture = CultureInfo.InvariantCulture;
             CultureInfo.CurrentUICulture = CultureInfo.InvariantCulture;
 #endif
-            try
-            {
+            try {
                 Image drawing = new Image(ImageDataFactory.Create(fullImagePath));
-            }
-            catch (Exception e)
-            {
+            } catch (Exception e) {
                 if (e.InnerException != null && e.InnerException.Message.Length > 18)
                     startOfMsg = e.InnerException.Message.Substring(0, 19);
             }
             NUnit.Framework.Assert.IsNotNull(startOfMsg);
             NUnit.Framework.Assert.AreNotEqual("Could not find file", startOfMsg);
         }
+        
+        [NUnit.Framework.Test]
+        [Ignore("Manual run only")]
+        public virtual void NetworkPathImageTest02() {
+            // TODO This test can work only if shared folder exists on some local network computer.
+            // Suggested apporach is to create such folder on your computer and input corresponding names as variables values below.
+            String comupterNameAndSharedFolderPath = @"INSERT_YOUR_COMPUTER_NAME"; // e.g. \\DESKTOP-ABCD3TQ\_inbox
+            String outPath = "INSERT_OUTPUT_PATH";
+            
+            String fullImagePath = @"\\" + comupterNameAndSharedFolderPath + @"\img.jpg";
+            Image drawing = new Image(ImageDataFactory.Create(fullImagePath));
+            Document doc = new Document(new PdfDocument(new PdfWriter(outPath)));
+            doc.Add(drawing.SetAutoScale(true));
+            doc.Close();
+        }
     }
-}
+}

itext/itext.io/itext/io/source/RandomAccessSourceFactory.cs

@@ -153,7 +153,10 @@ public IRandomAccessSource CreateSource(FileStream raf)
 		/// <exception cref="System.IO.IOException"/>
         public IRandomAccessSource CreateSource(Uri url) {
 #if !NETSTANDARD1_6
-            WebRequest wr = WebRequest.Create(url.LocalPath);
+			// Creation of web request via url.AbsoluteUri breaks UNC pathes (like \\computer-name\\img.jpg),
+			// url.LocalPath and url.AbsolutePath - break http links (like https://website.com/img.jpg).
+			// It seems enough to simply pass Uri instance as is, WebRequest seems to handle both escaping and UNC issues.
+            WebRequest wr = WebRequest.Create(url);
             wr.Credentials = CredentialCache.DefaultCredentials;
             Stream isp = wr.GetResponse().GetResponseStream();
 #else

itext/itext.io/itext/io/util/UrlUtil.cs

@@ -71,8 +71,10 @@ public static Uri ToURL(String filename) {
         public static Stream OpenStream(Uri url) {
             Stream isp;
             if (url.IsFile) {
-                // do not replace first argument with Uri.UnescapeDataString(url.AbsolutePath) instead of url.LocalPath
-                // it breaks the recognition of network paths
+                // Use url.LocalPath because it's needed for handling UNC pathes (like used in local
+                // networks, e.g. \\computer\file.ext). It's safe to use #LocalPath because we 
+                // check #IsFile beforehand. On the other hand, the url.AbsolutePath provides escaped string and also breaks
+                // UNC path.
                 isp = new FileStream(url.LocalPath, FileMode.Open, FileAccess.Read);     
             } else {
 #if !NETSTANDARD1_6