Set Console.OutputEncoding to UTF-8

Setting the OutputEncoding to Unicode caused characters to be written
incorrectly in some cases.  UTF-8 is the correct setting.

Author: daviwil

src/PowerShellEditorServices/Session/SessionPSHostUserInterface.cs

@@ -57,9 +57,9 @@ public ConsoleServicePSHostUserInterface(bool enableConsoleRepl)
         {
             if (enableConsoleRepl)
             {
-                // Set the output encoding to Unicode so that all
-                // Unicode characters are written correctly
-                System.Console.OutputEncoding = System.Text.Encoding.Unicode;
+                // Set the output encoding to UTF-8 so that special
+                // characters are written to the console correctly
+                System.Console.OutputEncoding = System.Text.Encoding.UTF8;
             }
 
             this.rawUserInterface =