Add project_reader in new RBAC tests

Tempest is fixing the bug#1964509 (depends-on) where
project_reader user will be created under the same project
as primary, project_member, project_admin users.

'primary', 'project_admin', 'project_member', and 'project_reader'
creds will be created in same projects. All the alt creds will be
created under the new projects. non alt and alt creds will use
different project, for example, 'project_alt_member' and
'project_member' creds will be created in different project.

Related-Bug: #1964509

Depends-On: https://review.opendev.org/c/openstack/tempest/+/871018
Change-Id: I143e69c1e150ddf7fa1757dea7bced6bff6739a9
6 files changed