Dev/overlay control (#278)

* Creating a control for the overlay

* using Interactivity

* trying to bind by reference

* fix bindings

* remove unused packages

* Move getter/setter to show method

* Convert to AutoProperty

* Make text copied notification configurable

* cache settings, removed unused file

FluentTerminal.Models/TerminalOptions.cs

@@ -23,5 +23,7 @@ namespace FluentTerminal.Models
         public int Padding { get; set; }
 
         public uint ScrollBackLimit { get; set; }
+
+        public bool ShowTextCopied { get; set; }
     }
 }