[RFE] disable case-sensitivity if user login by a case-insensitive IdP

1. Proposed title of this feature request
   • OpenShift should not introduce case-sensitivity on case insensitive IdPs.
2. What is the nature and description of the request?
   • OpenShift uses a case-sensitive authentication system. Some IdPs are case-insensitive, so that the following issue would arrise:
   • OCP configured with RH-SSO as IdP, user-federation with AD.
   • LDAP has a user "USER_1" configured, belonging to group "developers".
   • RH-SSO pulls in that user via user-federation and creates user "user_1" (as LDAP is case-insensitive).
   • OCP group sync created a group "developers" containing user "USER_1".
   • User "user_1" logs in at OCP, but does not belong to group "developers" as only "USER_1" instead of "user_1" is member.
   • Logging in as "USER_1" would result in the same missing membership as SSO will convert that username to "user_1".

3. Why does the customer need this? (List the business requirements here)

This is currently a blocker for my customer and they will have to work with their AD-team to change all uppercased users to lowercased users.

 
4. List any affected packages or components.

OpenShift authentication