* ucind: implement cluster list
I keep forgetting my ucind clusters, that add the missing list command:
```
% ./ucind cluster list
NAME MACHINES
miek1 machine-1
```
Just the name would have been enough, but to actually make use of the
tui table a machines list is handy as well.
(There isn't much bubbletea in ucind, but I thought lets start now).
Signed-off-by: Miek Gieben <miek@miek.nl>
* Filter directly when listing
Filter on ucind managed while listing clusters
Signed-off-by: Miek Gieben <miek@miek.nl>
---------
Signed-off-by: Miek Gieben <miek@miek.nl>
