TenantID is ignored in some cases

When ProjectID is not set, TenantID might be ignored in MAPO.

Context: When setting additional networks in Machine templates, networks can be identified by the means of a filter. The network filter has both TenantID and ProjectID as fields. TenantID was ignored.

Steps to reproduce:
Create a Machine or a MachineSet with a template containing a Network filter that sets a TenantID.

```
networks:

• filter:
  id: 'the-network-id'
  tenantId: '123-123-123'
  ```

One cheap way of testing this could be to pass a valid network ID and set a bogus tenantID. If the machine gets associated with the network, then tenantID has been ignored and the bug is present. If instead MAPO errors, then in means that it has taken tenantID into consideration.