"Recent" menu implemented (#585)

* Refactoring CommandHistoryService to prepare "Recent" menu item feature.

* "Recent" menu implemented, but still not bound to commands.

* "Recent" menu implemented.

FluentTerminal.App.ViewModels/ProfileCommandViewModel.cs

@@ -0,0 +1,19 @@
+using FluentTerminal.Models;
+using GalaSoft.MvvmLight;
+using GalaSoft.MvvmLight.Command;
+
+namespace FluentTerminal.App.ViewModels
+{
+    public class ProfileCommandViewModel : ViewModelBase
+    {
+        public ShellProfile Profile { get; }
+
+        public RelayCommand Command { get; }
+
+        public ProfileCommandViewModel(ShellProfile profile, RelayCommand command)
+        {
+            Profile = profile;
+            Command = command;
+        }
+    }
+}