Add the `vmware/scenario/vcenter_only` alias to be able to identify the
vmware test roles that can be tested with just on vcenter instance.
Also, add a check to be sure we don't try to attach ESXi hosts if none
has been defined.
Refactoring of the following roles to make use of the new
`prepare_vmware_tests` role.
- `vmware_inventory`
- `vmware_local_role_facts`
- `vmware_local_role_manager`
- `vmware_local_user_facts`
- `vmware_local_user_manager`
- `vmware_maintenancemode`
- `vmware_portgroup_facts`
- `vmware_resource_pool`
- `vmware_resource_pool_facts`
This patch depends on: https://github.com/ansible/ansible/pull/55719
Original PR: https://github.com/ansible/ansible/pull/54882
* Update Shippable integration test groups.
* Update integration test group aliases.
* Rebalance AWS and Azure tests with extra group.
* Rebalance Windows tests with another group.
