Select control population is not scoped to the tenant.

When creating a new Slave Template, the select controls (e.g. Networks) are populated with every network to which the user has access - not just those for the particular tenant being used.

This means that a network or an image can be selected when they're not actually accessible from the specific tenant.

Not sure if the `openstack4j` interface supports filtering lists but, if so, it should be possible to pass the tenant ID to to the openstack API call.