Make it easy to configure the schemas that should be sent to the AutomationClient

When AutomationServer send a Document to the client via JSON it won't serialize all the properties : only the basic info (id, path ...) and a minimal set of properties will be sent.

By setting the X-NXDocumentProperties the client can force the server to export all properties for a list of schemas.

It can be set at request level.

However, setting this value on each requests may be painful.
The idea is to allow to define a default value at Session level that will be automatically set at Request level if no specific setting was provided.