OSNG-45 generalized set fields

generalized setfields to make it easier to write provisioning classes to wrap those SCIM classes to entity classes.

ATM you have to follow a few rules:
1. the names of the fields in your entity must be equal to the names used in the ScimSchema
2. if your Entity is an implementation of a multi value object it must implement ChildOfMultiValueAttribute
3. the lists of your entity must be initialized
renamed Wrapping classes