Enable raw keyboard input

In order for applications to receive all keyboard inputs, including the
Ctrl-C and Ctrl-Z, the raw input mode has been enabled. As result the
SIGINT will no longer be used, instead the keyboard Ctrl-C event is used
for exiting the framework, but only if no components has made use of it.

include/ftxui/component/mouse.hpp

@@ -16,6 +16,8 @@ struct Mouse {
     None = 3,
     WheelUp = 4,
     WheelDown = 5,
+    WheelLeft = 6,   /// Supported terminal only.
+    WheelRight = 7,  /// Supported terminal only.
   };
 
   enum Motion {