Use /ToUnicode mappings to several chars during text extraction from simple fonts

Refactor existing PdfFont#decode(PdfString) and PdfFont#getContentWidth(PdfString) methods

DEVSIX-1681

Autoported commit.
Original commit hash: [9a3157e04]

Author: Snipx

itext.tests/itext.kernel.tests/itext/kernel/pdf/canvas/parser/SimpleFontToUnicodeExtractionTest.cs

@@ -0,0 +1,38 @@
+using System;
+using iText.Kernel.Pdf;
+using iText.Kernel.Pdf.Canvas.Parser.Listener;
+using iText.Test;
+
+namespace iText.Kernel.Pdf.Canvas.Parser {
+    public class SimpleFontToUnicodeExtractionTest : ExtendedITextTest {
+        private static readonly String sourceFolder = iText.Test.TestUtil.GetParentProjectDirectory(NUnit.Framework.TestContext
+            .CurrentContext.TestDirectory) + "/resources/itext/kernel/parser/SimpleFontToUnicodeExtractionTest/";
+
+        /// <exception cref="System.IO.IOException"/>
+        [NUnit.Framework.Test]
+        public virtual void Test01() {
+            PdfDocument pdfDocument = new PdfDocument(new PdfReader(sourceFolder + "simpleFontToUnicode01.pdf"));
+            String expected = "Information plays a central role in soci-\n" + "ety today, and it is becoming more and \n"
+                 + "more common for that information to \n" + "be offered in digital form alone. The re-\n" + "liable, user-friendly Portable Document \n"
+                 + "Format (PDF) has become the world’s \n" + "file type of choice for providing infor-\n" + "mation as a digital document. \n"
+                 + "Tags can be added to a PDF in order \n" + "to structure the content of a document. \n" + "These tags are a critical requirement if \n"
+                 + "any form of assistive technology (such \n" + "as screen readers, specialist mice, and \n" + "speech recognition and text-to-speech \n"
+                 + "software) is to gain access to this con-\n" + "tent. To date, PDF documents have rare-\n" + "ly been tagged, and not all software can \n"
+                 + "make use of PDF tags. In practical terms, \n" + "this particularly reduces information‘s \n" + "accessibility for people with disabilities \n"
+                 + "who rely on assistive technology.";
+            String actualText = PdfTextExtractor.GetTextFromPage(pdfDocument.GetPage(1), new LocationTextExtractionStrategy
+                ());
+            NUnit.Framework.Assert.AreEqual(expected, actualText);
+        }
+
+        /// <exception cref="System.IO.IOException"/>
+        [NUnit.Framework.Test]
+        public virtual void Test02() {
+            PdfDocument pdfDocument = new PdfDocument(new PdfReader(sourceFolder + "simpleFontToUnicode02.pdf"));
+            String expected = "ffaast";
+            String actualText = PdfTextExtractor.GetTextFromPage(pdfDocument.GetPage(1), new LocationTextExtractionStrategy
+                ());
+            NUnit.Framework.Assert.AreEqual(expected, actualText);
+        }
+    }
+}

itext.tests/itext.kernel.tests/itext/kernel/pdf/canvas/parser/TextRenderInfoTest.cs

@@ -79,7 +79,7 @@ public virtual void TestCharacterRenderInfos() {
         /// </remarks>
         /// <exception cref="System.Exception"/>
         [NUnit.Framework.Test]
-        [LogMessage(iText.IO.LogMessageConstant.COULD_NOT_FIND_GLYPH_WITH_CODE)]
+        [LogMessage(iText.IO.LogMessageConstant.COULD_NOT_FIND_GLYPH_WITH_CODE, Count = 2)]
         public virtual void TestUnicodeEmptyString() {
             StringBuilder sb = new StringBuilder();
             String inFile = "japanese_text.pdf";