Fixes #92. Remove dependency on ustring. (#2620)

* Remove NStack and replace ustring to string.

* Add unit test and improving some code.

* Adjust code and fix all unit tests errors.

* Add XML Document and move the Rune folder into the Text folder.

* Improve unit tests with byte array on DecodeRune and DecodeLastRune.

* Fix unit test.

* 😂Code review

* Reduce unit tests code.

* Change StringExtensions.Make to StringExtensions.ToString and added some more unit tests.

* Fix merge errors.

* Remove GetTextWidth and calls replaced with StringExtensions.GetColumns.

* Hack to use UseSystemConsole passed in the command line arguments.

* Revert "Hack to use UseSystemConsole passed in the command line arguments."

This reverts commit b74d11c786.

* Remove Application.UseSystemConsole from the config file.

* Fix errors related by removing UseSystemConsole from the config file.

* Fixes #2633. DecodeEscSeq throw an exception if cki is null.

* Fix an exception if SelectedItem is -1.

* Set SelectedItem to 0 and remove unnecessary ToString.

* Using a unique ToString method for Rune and other for byte.

* Fix a bug where a wider rune is added with only a width of 1.

* Force the SelectedGlyph is the one that was typed after jumpList is executed.

* Added more InlineData to RuneTests.

* Reducing significantly the code by using Theory attribute in the TextFormatterTests.

* Override PositionCursor to handle the CharMap cursor position.

* Fix merge errors.

* Minor tweaks to API docs

---------

Co-authored-by: Tig Kindel <tig@users.noreply.github.com>

UnitTests/Views/TextViewTests.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
+using System.Text;
 using System.Text.RegularExpressions;
 using Xunit;
 using Xunit.Abstractions;
@@ -31,13 +32,10 @@ namespace Terminal.Gui.ViewsTests {
 
 				//                   1         2         3 
 				//         01234567890123456789012345678901=32 (Length)
-				var buff = new byte [txt.Length];
-				for (int i = 0; i < txt.Length; i++) {
-					buff [i] = (byte)txt [i];
-				}
+				var buff = Encoding.Unicode.GetBytes(txt);
 				var ms = new System.IO.MemoryStream (buff).ToArray ();
 				_textView = new TextView () { Width = 30, Height = 10 };
-				_textView.Text = ms;
+				_textView.Text = Encoding.Unicode.GetString (ms);
 			}
 
 			public override void After (MethodInfo methodUnderTest)
@@ -987,12 +985,12 @@ namespace Terminal.Gui.ViewsTests {
 					_textView.ProcessKey (new KeyEvent (Key.K | Key.CtrlMask, new KeyModifiers ()));
 					Assert.Equal (0, _textView.CursorPosition.X);
 					Assert.Equal (0, _textView.CursorPosition.Y);
-					Assert.Equal ("", _textView.Text.ToString ());
-					Assert.Equal ($"This is the first line.{Environment.NewLine}This is the second line.", Clipboard.Contents.ToString ());
+					Assert.Equal ("", _textView.Text);
+					Assert.Equal ($"This is the first line.{Environment.NewLine}This is the second line.", Clipboard.Contents);
 
 					// Paste
 					_textView.ProcessKey (new KeyEvent (Key.Y | Key.CtrlMask, new KeyModifiers ()));
-					Assert.Equal ($"This is the first line.{Environment.NewLine}This is the second line.", _textView.Text.ToString ());
+					Assert.Equal ($"This is the first line.{Environment.NewLine}This is the second line.", _textView.Text);
 					break;
 				default:
 					iterationsFinished = true;
@@ -1895,7 +1893,7 @@ namespace Terminal.Gui.ViewsTests {
 
 			for (int i = lCount; i >= 0; i--) {
 				var r = line [i];
-				sumLength += Rune.ColumnWidth (r);
+				sumLength += ((Rune)r).GetColumns ();
 				if (r == '\t') {
 					sumLength += tabWidth + 1;
 				}
@@ -2014,7 +2012,7 @@ namespace Terminal.Gui.ViewsTests {
 				Assert.Equal (8, tv.Text.Length);
 				Assert.Equal (text, tv.Text);
 				Assert.False (tv.IsDirty);
-				Assert.Equal ('\u2400', ConsoleDriver.MakePrintable ((Rune)tv.Text [4]));
+				Assert.Equal ((Rune)'\u2400', ((Rune)tv.Text [4]).MakePrintable ());
 			}
 		}
 
@@ -2200,21 +2198,21 @@ line.
 			var txt = "This is a text.";
 			var txtRunes = TextModel.ToRunes (txt);
 			Assert.Equal (txt.Length, txtRunes.Count);
-			Assert.Equal ('T', txtRunes [0]);
-			Assert.Equal ('h', txtRunes [1]);
-			Assert.Equal ('i', txtRunes [2]);
-			Assert.Equal ('s', txtRunes [3]);
-			Assert.Equal (' ', txtRunes [4]);
-			Assert.Equal ('i', txtRunes [5]);
-			Assert.Equal ('s', txtRunes [6]);
-			Assert.Equal (' ', txtRunes [7]);
-			Assert.Equal ('a', txtRunes [8]);
-			Assert.Equal (' ', txtRunes [9]);
-			Assert.Equal ('t', txtRunes [10]);
-			Assert.Equal ('e', txtRunes [11]);
-			Assert.Equal ('x', txtRunes [12]);
-			Assert.Equal ('t', txtRunes [13]);
-			Assert.Equal ('.', txtRunes [^1]);
+			Assert.Equal ('T', txtRunes [0].Value);
+			Assert.Equal ('h', txtRunes [1].Value);
+			Assert.Equal ('i', txtRunes [2].Value);
+			Assert.Equal ('s', txtRunes [3].Value);
+			Assert.Equal (' ', txtRunes [4].Value);
+			Assert.Equal ('i', txtRunes [5].Value);
+			Assert.Equal ('s', txtRunes [6].Value);
+			Assert.Equal (' ', txtRunes [7].Value);
+			Assert.Equal ('a', txtRunes [8].Value);
+			Assert.Equal (' ', txtRunes [9].Value);
+			Assert.Equal ('t', txtRunes [10].Value);
+			Assert.Equal ('e', txtRunes [11].Value);
+			Assert.Equal ('x', txtRunes [12].Value);
+			Assert.Equal ('t', txtRunes [13].Value);
+			Assert.Equal ('.', txtRunes [^1].Value);
 
 			int col = 0;
 			Assert.True (TextModel.SetCol (ref col, 80, 79));
@@ -2224,11 +2222,11 @@ line.
 			var start = 0;
 			var x = 8;
 			Assert.Equal (8, TextModel.GetColFromX (txtRunes, start, x));
-			Assert.Equal ('a', txtRunes [start + x]);
+			Assert.Equal ('a', txtRunes [start + x].Value);
 			start = 1;
 			x = 7;
 			Assert.Equal (7, TextModel.GetColFromX (txtRunes, start, x));
-			Assert.Equal ('a', txtRunes [start + x]);
+			Assert.Equal ('a', txtRunes [start + x].Value);
 
 			Assert.Equal ((15, 15), TextModel.DisplaySize (txtRunes));
 			Assert.Equal ((6, 6), TextModel.DisplaySize (txtRunes, 1, 7));