Enable mouse input by default.

lib/src/ui/controller.dart

@@ -10,7 +10,7 @@ import 'package:xterm/src/ui/selection_mode.dart';
 class TerminalController with ChangeNotifier {
   TerminalController({
     SelectionMode selectionMode = SelectionMode.line,
-    PointerInputs pointerInputs = const PointerInputs.none(),
+    PointerInputs pointerInputs = const PointerInputs({PointerInput.tap}),
     bool suspendPointerInput = false,
   })  : _selectionMode = selectionMode,
         _pointerInputs = pointerInputs,