Display association status

[anmazzotti]

Closes #44

This adds more display information:

# kubectl get machines && kubectl get elementalmachines && kubectl get elementalhosts
NAME                                        CLUSTER                 NODENAME                                 PROVIDERID                                                   PHASE     AGE   VERSION
elemental-cluster-k3s-control-plane-6mw2p   elemental-cluster-k3s   m-d9e3bb70-3a82-4f01-8bcd-e5a6d6b5f67d   elemental://default/m-d9e3bb70-3a82-4f01-8bcd-e5a6d6b5f67d   Running   14m   v1.28.5+k3s1
NAME                                        CLUSTER                 MACHINE                                     PROVIDERID                                                   READY   AGE
elemental-cluster-k3s-control-plane-q2td6   elemental-cluster-k3s   elemental-cluster-k3s-control-plane-6mw2p   elemental://default/m-d9e3bb70-3a82-4f01-8bcd-e5a6d6b5f67d   True    14m
NAME                                     CLUSTER                 MACHINE                                     ELEMENTALMACHINE                            READY   AGE
m-d9e3bb70-3a82-4f01-8bcd-e5a6d6b5f67d   elemental-cluster-k3s   elemental-cluster-k3s-control-plane-6mw2p   elemental-cluster-k3s-control-plane-q2td6   True    13m

Note that there is a sneaky change too.
The machine-name label used on hosts now reflects the CAPI Machine name, and not the ElementalMachine name as previously.
Functionally this does not have any effect, the controller only checks whether the label exists when finding host candidates, the value does not matter.

Since the ElementalMachine is already referenced in the Host spec, I thought it would be nice to use the machine-name label to propagate the CAPI machine name instead.

[davidcassany]

Nice 👍