Add context menu into sidebar (#4044)

src/renderer/components/hotbar/hotbar-entity-icon.tsx

@@ -44,20 +44,16 @@ interface Props extends DOMAttributes<HTMLElement> {
 
 @observer
 export class HotbarEntityIcon extends React.Component<Props> {
-  @observable private contextMenu: CatalogEntityContextMenuContext;
+  @observable private contextMenu: CatalogEntityContextMenuContext = {
+    menuItems: [],
+    navigate: (url: string) => navigate(url),
+  };
 
   constructor(props: Props) {
     super(props);
     makeObservable(this);
   }
 
-  componentDidMount() {
-    this.contextMenu = {
-      menuItems: [],
-      navigate: (url: string) => navigate(url),
-    };
-  }
-
   get kindIcon() {
     const className = "badge";
     const category = catalogCategoryRegistry.getCategoryForEntity(this.props.entity);