To Implement new Role Assignments tab for specific Cluster.
as it is done for Users, this is about to include RoleAssignmentList component, based on the role assignments related with specific cluster

Things to consider:

• the tab (not even to display the tab element should be behind ACM_ACCESS_CONTROL_MANAGEMENT feature flag)
• cluster column should be hidden. use/extend "hiddenColumns" see https://github.com/stolostron/console/blob/e581ae3a0315697be61c79cd9781eef1c9e601fb/frontend/src/routes/UserManagement/RoleAssignment/RoleAssignments.tsx#L30