Add several endpoints

Client/src/Pages/Auth/Login.jsx

@@ -249,7 +249,7 @@ const Login = () => {
 
   useEffect(() => {
     axiosInstance
-      .get("/auth/users/admin")
+      .doesAdminExist()
       .then((response) => {
         if (response.data.data === false) {
           navigate("/register");

Client/src/Pages/Auth/Register/Register.jsx

@@ -397,9 +397,7 @@ const Register = ({ isAdmin }) => {
     const fetchInvite = async () => {
       if (token !== undefined) {
         try {
-          const res = await axiosInstance.post(`/auth/invite/verify`, {
-            token,
-          });
+          const res = await axiosInstance.verifyInvitationToken(token);
           const { role, email } = res.data.data;
           console.log(role);
           setForm({ ...form, email, role });