feat: dyn reaction

Signed-off-by: dom <githubaccount56556@proton.me>

lib/models_new/dynamic/dyn_reaction/item.dart

@@ -0,0 +1,21 @@
+class DynReactionItem {
+  String? action;
+  String? face;
+  String? mid;
+  String? name;
+
+  DynReactionItem({
+    this.action,
+    this.face,
+    this.mid,
+    this.name,
+  });
+
+  factory DynReactionItem.fromJson(Map<String, dynamic> json) =>
+      DynReactionItem(
+        action: json['action'] as String?,
+        face: json['face'] as String?,
+        mid: json['mid'] as String?,
+        name: json['name'] as String?,
+      );
+}