feat: support admin assign superuser in admin ui (#12798)

### What problem does this PR solve?

Allow superuser(admin) to grant or revoke other superuser.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

web/src/utils/api.ts

@@ -263,6 +263,8 @@ export default {
   adminLogout: `${ExternalApi}${api_host}/admin/logout`,
   adminListUsers: `${ExternalApi}${api_host}/admin/users`,
   adminCreateUser: `${ExternalApi}${api_host}/admin/users`,
+  adminSetSuperuser: (username: string) =>
+    `${ExternalApi}${api_host}/admin/users/${username}/admin`,
   adminGetUserDetails: (username: string) =>
     `${ExternalApi}${api_host}/admin/users/${username}`,
   adminUpdateUserStatus: (username: string) =>

web/src/utils/authorization-util.ts

@@ -13,7 +13,8 @@ const storage = {
     return localStorage.getItem(UserInfo);
   },
   getUserInfoObject: () => {
-    return JSON.parse(localStorage.getItem('userInfo') || '');
+    const userInfoStr = localStorage.getItem(UserInfo);
+    return userInfoStr ? JSON.parse(userInfoStr) : null;
   },
   setAuthorization: (value: string) => {
     localStorage.setItem(Authorization, value);