Add VM classes and Storage policies to Org Region Quotas

[adambarreiro]

This PR:

• Adds a new Set argument to vcfa_org_region_quota named region_vm_class_ids that allows to assign VM classes to the Region Quota.
• Adds a new data source vcfa_region_vm_class to fetch these VM Classes from an existing Region.
• Adds a new Set argument to vcfa_org_region_quota named region_storage_policy that allows assigning Region Storage Policies to the given Region Quota.
• Renames vcfa_org_vdc to vcfa_org_region_quota and all Vdc, VDC, vdc occurrences to new Region Quota naming.
• vdc parameter from Provider configuration is removed as it doesn't make much sense.

Required new properties in vcfa_test_config.json:

"tm": {
    "regionVmClasses": ["best-effort-4xlarge", "best-effort-8xlarge"],
}

[Didainius]

LGTM

[lvirbalas]

Tried manually. Works beautifully.