Authenticates and creates a session for a user

To access the API, a user must have the required permissions set in Infinity for the supplied WebApiClient.

If authentication is successful, a .AspNet.ApplicationCookie cookie will be stored automatically for use with the methods that require authentication.

NOTE: You can access the cookie by using Developer Tools in your browser and checking the response headers if required.

If your session expires, you will need to run the login method again