Create object and commands to assign global permission (#473)

vCenter UI provides functionality to set 'global permissions' for accounts:
https://docs.vmware.com/en/VMware-vSphere/8.0/vsphere-security/GUID-C7702E31-1623-4189-89CB-E1136AA27972.html
However, there is no automation for this operation.

The approach taken is to communicate with vCenter MOB and execute the
request modelling browser operation.

Signed-off-by: Vladimir Bespalov <[email protected]>