Add a last seen time on the cli's status command, similar to the web
portal.
Before:
```
100.xxx.xxx.xxx tailscale-operator tagged-devices linux offline
```
After:
```
100.xxx.xxx.xxx tailscale-operator tagged-devices linux offline, last seen 20d ago
```
Fixes#16584
Signed-off-by: Mahyar Mirrashed <mah.mirr@gmail.com>