feature exchange rate update automation

Automated downloading exchange rates from HMRC and updating the database. Added function call to the console and form applications.

Also added a form to show the console output in form application.

src/bnhtrade.gui/FormConsole.cs

@@ -0,0 +1,44 @@
+using ConsoleRedirection;
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace bnhtrade.gui
+{
+    public partial class FormConsole : Form
+    {
+        // That's our custom TextWriter class
+        TextWriter _writer = null;
+
+        public FormConsole()
+        {
+            InitializeComponent();
+        }
+
+        private void FormConsole_Load(object sender, EventArgs e)
+        {
+            // Instantiate the writer
+            _writer = new TextBoxStreamWriter(txtConsole);
+            // Redirect the out Console stream
+            Console.SetOut(_writer);
+        }
+
+        // This is called when the "Say Hello" button is clicked
+        private void txtSayHello_Click(object sender, EventArgs e)
+        {
+            // Writing to the Console now causes the text to be displayed in the text box.
+            Console.WriteLine("Hello world");
+        }
+
+        private void button1_Click(object sender, EventArgs e)
+        {
+            this.Close();
+        }
+    }
+}