dns: dynamic: op-mode: provide "restart dns dynamic" command
dns: dynamic: op-mode: provide "restart dns dynamic" command

... this is actually a copy of the weird "update dns dynamic" command. Some
users like restart more thus both CLI notions will call the same backend
script .

vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x