Include Custom Role Assignment in SSO

Today, the ProductRole attribute can be included in SSO configuration (for some identity providers) in conjunction with the ProductPrefix attribute when provisioning users. It would be useful for Enterprise+ users to also have another attribute for assigning Custom Roles at scale. Custom Roles are very helpful when managing a large user base with varied permission needs and being able to define this in the SSO IDP would help with greater efficiency and management of users.