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/pages/video/member/view.dart

@@ -259,7 +259,7 @@ class _HorizontalMemberPageState extends State<HorizontalMemberPage>
       Obx(
         () => Row(
           children: List.generate(5, (index) {
-            if (index % 2 == 0) {
+            if (index.isEven) {
               return _buildChildInfo(
                 theme: theme,
                 title: const ['粉丝', '关注', '获赞'][index ~/ 2],