swadm link set-prop broke in structopt -> clap transition

[Nieuwejaar]

When swadm migrated from using structopt to clap for its CLI, we lost the ability to disable a link using set-prop:.

root@oxz_switch1:~# swadm link get rear0/0
Port/Link  Media   Speed  FEC  Autoneg  Enabled  State    MAC
rear0/0    Copper  100G   RS   true     true     Unknown  a8:40:25:05:07:03
root@oxz_switch1:~# swadm link set-prop rear0/0 enabled false
error: 0 values required for '[ENABLED]' but 1 was provided

Usage: swadm link set-prop <LINK> enable [ENABLED]

For more information, try '--help'.
root@oxz_switch1:~# swadm link get rear0/0
Port/Link  Media   Speed  FEC  Autoneg  Enabled  State    MAC
rear0/0    Copper  100G   RS   true     true     Unknown  a8:40:25:05:07:03

To disable a link, you now have to use swadm link <link> disable rather than set-prop:

root@oxz_switch1:~# swadm link get rear0/0
Port/Link  Media   Speed  FEC  Autoneg  Enabled  State    MAC
rear0/0    Copper  100G   RS   true     true     Unknown  a8:40:25:05:07:03
root@oxz_switch1:~# swadm link disable rear0/0
root@oxz_switch1:~# swadm link get rear0/0
Port/Link  Media   Speed  FEC  Autoneg  Enabled  State    MAC
rear0/0    Copper  100G   RS   true     false    Unknown  a8:40:25:05:07:03

I believe this is because the explicit parse was omitted:

     /// Set whether the link is enabled.
-    #[structopt(visible_alias = "ena")]
-    Enabled {
-        #[structopt(parse(try_from_str))]
-        enabled: bool,
-    },
+    #[clap(visible_alias = "ena")]
+    Enabled { enabled: bool },

This means that we can't disable autonegotiation, kr mode, nat-only mode, and ipv6 for links at all, since there is no special-case command for them.

Weirdly, we can no longer use set-prop to enable a link either:

root@oxz_switch1:~# swadm link get rear0/0
Port/Link  Media   Speed  FEC  Autoneg  Enabled  State    MAC
rear0/0    Copper  100G   RS   true     false    Unknown  a8:40:25:05:07:03
root@oxz_switch1:~# swadm link set-prop rear0/0 enabled
root@oxz_switch1:~# swadm link get rear0/0
Port/Link  Media   Speed  FEC  Autoneg  Enabled  State    MAC
rear0/0    Copper  100G   RS   true     false    Unknown  a8:40:25:05:07:03
root@oxz_switch1:~# swadm link enable rear0/0
root@oxz_switch1:~# swadm link get rear0/0
Port/Link  Media   Speed  FEC  Autoneg  Enabled  State    MAC
rear0/0    Copper  100G   RS   true     true     Unknown  a8:40:25:05:07:03

The command succeeds, but doesn't actually do anything.