2. polish user controller's codes
3. add an unfinished profile page

now server can create login cookie and client can store cookie in broser. We use userId as token for login cookie for convinence for now.

2. server return session token with Usermodel after successfully login -> store login status in vuex
3. add log out button -> clear token in localstorage and login status in vuex
4. now we can define each route whether it needs auth (login status) to continue redirecting