Make watch a top-level command.

[tshowers-bt]

Create a peer watch command that runs a subcommand in a loop and displays the latest output. At a minimum we need to be able to watch the show command, but the idea is to be able to watch other commands (maybe any command) without much extra effort going forward.

It might be wise to have the command take the form peer watch <watch-args> <subcmd> <subcmd-args> if possible.

• peer watch show <show-args> provides the same behaviour that peer show -w <show-args> does
• peer show -w <show-args> is deprecated in favour of peer watch show <show-args>

[Insomniak47]

I know we had talked about this before but I thought we decided on embedding it in because there were a few commands we planned on supporting that it didn't really work with (open, for ex)