fix: Update OAuth implementation 3

Author: reeshika-h

src/main/java/com/contentstack/cms/oauth/OAuthHandler.java

@@ -117,9 +117,7 @@ private void generatePkceParameters() {
      */
     public String authorize() {
         try {
-            String baseUrl = String.format("%s/#!/apps/%s/authorize", 
-                config.getFormattedAuthorizationEndpoint(), 
-                config.getAppId());
+            String baseUrl = config.getFormattedAuthorizationEndpoint();
 
             StringBuilder urlBuilder = new StringBuilder(baseUrl);
             urlBuilder.append("?response_type=").append(config.getResponseType())