refactor: move component into a single package (#898)

packages/component/src/styles/utils/localStorageThemeHelper.ts

@@ -0,0 +1,13 @@
+import { ThemeMode } from '../types';
+
+export class LocalStorageThemeHelper {
+  name = 'Affine-theme-mode';
+  get = (): ThemeMode | null => {
+    return localStorage.getItem(this.name) as ThemeMode | null;
+  };
+  set = (mode: ThemeMode) => {
+    localStorage.setItem(this.name, mode);
+  };
+}
+
+export const localStorageThemeHelper = new LocalStorageThemeHelper();