tweaks (#1142)

* opt: unused layout

* mod: semantics

* opt: DanmakuMsg type

* opt: avoid cast

* opt: unnecessary_lambdas

* opt: use isEven

* opt: logger

* opt: invalid common page

* tweak

* opt: unify DynController

lib/common/widgets/stat/stat.dart

@@ -27,6 +27,7 @@ class StatWidget extends StatelessWidget {
       children: [
         Icon(
           type.iconData,
+          semanticLabel: type.label,
           size: iconSize,
           color: color,
         ),