slapos_erp5&cloud: Reimplement (and speed up) security to use...

slapos_erp5&cloud: Reimplement (and speed up) security to use ERP5User_getUserSecurityCategoryValueList

 No need external script for this.

 This change introduces a test change on testSlapOSCloudShadow, that
 include R-COMPUTER and R-INSTANCE for shadow users.

 After check, this feature (shadow) is not used for compute node or
 software instance users, so despite it is not needed (introduced 12yr
 ago), I kept just for reference.

 If those tests eventually break or cause problem, it is safe to remove
 them later on.