Add cloud server reboot to plans

[sgsullivan]

adds cloud server reboot to plans and makes the cmd flag support passing multiple uniq-ids.

ssullivan@data ~ $ lw cloud server reboot --uniq-id Y7WB19,KYC8SM
Rebooted: Y7WB19
Rebooted: KYC8SM
ssullivan@data ~ $ lw cloud server status --uniq-id Y7WB19,KYC8SM
UniqId: Y7WB19
        domain: y8s8.k7uesbx5as.io
        status: Rebooting
        detailed status: Shutting down server
        running: [{CurrentStep:8 DetailedStatus:Shutting down server Name:Clean Reboot Status:Rebooting}]
        progress: 0
UniqId: KYC8SM
        domain: xc4h.n4e097cvma.io
        status: Rebooting
        detailed status: Shutting down server
        running: [{CurrentStep:8 DetailedStatus:Shutting down server Name:Clean Reboot Status:Rebooting}]
        progress: 0
ssullivan@data ~ $ 

Also works via the plan example:

ssullivan@data ~ $ lw plan --file examples/plans/cloud.server.reboot.yaml --var uniq_id=Y7WB19 --var uniq_id2=KYC8SM
Rebooted: Y7WB19
Rebooted: KYC8SM
ssullivan@data ~ $