Add check method for inspecting the access token

[arn-the-long-beard]

Overview of feature 📝

Have a method on the front end and a path to backend
Implement backend logic

Which problem is the feature or enhancement solving❓

We need to inspect the token on the backend to verify its authenticity

Documentation & Help ℹ️

https://github.com/WF-Engineering/facebook-rs/blob/master/src/models.rs

[arn-the-long-beard]

This is about a api call on back end to verify the token. It is out of scope on the front_end.