Add deletion subcommands to `lava-server manage`
lava-server manage interface is very convenient for automated LAVA deployments and remote management by systems such as ansible. However it still lacks some subcommands such as deletion (e.g.
lava-server manage user delete) or creation (e.g.
lava-server manage site add). Is there a reason for this? I'd be happy to issue a MR with these extra subcommands for completion.