Scripting "httpClient" dependencies must be added to whitelist

In the scripting API the httpClient.post and httpClient.get methods return a warning message at runtime to inform the user to use the send method. In order to use the send method you need to import and whitelist some classes.

The whitelist should be updated to include the required classes and utility methods should be added to httpClient for creating the prerequisite Request object.

Consider updating the policy example script to demonstrate the usage of httpClient.send