Printing mails. (#471)

* Implemented printing functionality.

* Implemented icon for printing.

* Remove debug code.

Wino.Messages/Client/Mails/PrintMailRequested.cs

@@ -0,0 +1,9 @@
+namespace Wino.Messaging.Client.Mails
+{
+    /// <summary>
+    /// When print mail is requested.
+    /// </summary>
+    /// <param name="PDFFilePath">Path to PDF file that WebView2 saved the html content as PDF.</param>
+    /// <param name="PrintTitle">Printer title on the dialog.</param>
+    public record PrintMailRequested(string PDFFilePath, string PrintTitle);
+}