`hostname` seems not to be in `holod` configuration

[frederic-loui]

When using remote holi-cli on several nodes, the hostname is always set to holo.

• Changing the hostname has no effect.

  ❯ target/debug/holo-cli --address http://clab-ripv2-freertr-rt6:50051
  holo#
  holo#
  holo# configure
  holo(config)# hostname R6
  R6(config)# commit
  % configuration committed successfully
  R6(config)# exit
  R6# exit

• exit and log again

  holo# exit
  ❯ target/debug/holo-cli --address http://clab-ripv2-freertr-rt6:50051
  holo#
  holo#
  holo#

• Issuing show running also show no hostname:

❯ target/debug/holo-cli --address http://clab-ripv2-freertr-rt6:50051
holo# show running
!
interfaces interface lo
 type iana-if-type:ethernetCsmacd
 ipv4
!
interfaces interface eth1
 type iana-if-type:ethernetCsmacd
 ipv4
!
interfaces interface eth2
 type iana-if-type:ethernetCsmacd
 ipv4
!
routing control-plane-protocols control-plane-protocol ietf-rip:ripv2 main
 !
 rip interfaces interface lo
 !
 rip interfaces interface eth1
 !
 rip interfaces interface eth2
!

[rwestphal]

I agree. The current "hostname" command feels more like a gimmick than anything useful.

I believe the best course of action is to implement the 'ietf-system' module, which would provide us with the 'system hostname STRING' command. Then, the CLI should use the hostname from the running configuration in the prompt.