#487 Handled Space and Enter events for Radiobox (#491)

Return true when an event a RadioBox is state change due to pressing Return or space.

Co-authored-by: ArthurSonzogni <sonzogniarthur@gmail.com>

src/ftxui/component/radiobox.cpp

@@ -103,8 +103,8 @@ class RadioboxBase : public ComponentBase {
 
     if (event == Event::Character(' ') || event == Event::Return) {
       *selected_ = hovered_;
-      //*selected_ = focused_entry();
       option_->on_change();
+      return true;
     }
 
     return false;