API CHANGE: sysadm/iocage - "action"="listplugins"

Add this API call to list all the available plugins for iocage.

REST Request (example):
-------------------------------
PUT /sysadm/iocage
{
   "action" : "listplugins"
}

WebSocket Request:
-------------------------------
{
   "namespace" : "sysadm",
   "args" : {
      "action" : "listplugins"
   },
   "name" : "iocage",
   "id" : "fooid"
}

Response:
-------------------------------
{
  "args": {
    "listplugins": {
      "remote": {
        "btsync": {
          "description": "Resilient, fast and scalable file sync software for enterprises and individuals.",
          "id": "btsync",
          "name": "BitTorrent Sync"
        },
        "couchpotato": {
          "description": "CouchPotato is an automatic NZB and torrent downloader.",
          "id": "couchpotato",
          "name": "CouchPotato"
        },
        "crashplan": {
          "description": "Computer backup and data storage made simple.",
          "id": "crashplan",
          "name": "Crashplan"
        },
        "deluge": {
          "description": "Bittorrent client using Python, and libtorrent-rasterbar",
          "id": "deluge",
          "name": "Deluge"
        },
        "emby": {
          "description": "Home media server built using mono and other open source technologies",
          "id": "emby",
          "name": "Emby"
        },
        "gitlab": {
          "description": "Powerful features for modern software development",
          "id": "gitlab",
          "name": "GitLab"
        },
        "jenkins": {
          "description": "Jenkins CI",
          "id": "jenkins",
          "name": "Jenkins"
        },
        "jenkins-lts": {
          "description": "Jenkins CI (Long Term Support Version)",
          "id": "jenkins-lts",
          "name": "Jenkins (LTS)"
        },
        "madsonic": {
          "description": "Open-source web-based media streamer and jukebox.",
          "id": "madsonic",
          "name": "MadSonic"
        },
        "nextcloud": {
          "description": "Access, share and protect your files, calendars, contacts, communication & more at home and in your enterprise.",
          "id": "nextcloud",
          "name": "NextCloud"
        },
        "plexmediaserver": {
          "description": "The Plex media server system",
          "id": "plexmediaserver",
          "name": "Plex Media Server"
        },
        "plexmediaserver-plexpass": {
          "description": "The Plex media server system",
          "id": "plexmediaserver-plexpass",
          "name": "Plex Media Server (PlexPass)"
        },
        "quasselcore": {
          "description": "Quassel Core is a daemon/headless IRC client, part of Quassel, that supports 24/7 connectivity. Quassel Client can be attached to it to.",
          "id": "quasselcore",
          "name": "Quasselcore"
        },
        "sickrage": {
          "description": "Automatic Video Library Manager for TV Shows",
          "id": "sickrage",
          "name": "SickRage"
        },
        "sonarr": {
          "description": "PVR for Usenet and BitTorrent users",
          "id": "sonarr",
          "name": "Sonarr"
        },
        "subsonic": {
          "description": "Open-source web-based media streamer and jukebox.",
          "id": "subsonic",
          "name": "SubSonic"
        },
        "syncthing": {
          "description": "Personal cloud sync",
          "id": "syncthing",
          "name": "Syncthing"
        },
        "transmission": {
          "description": "Fast and lightweight daemon BitTorrent client",
          "id": "transmission",
          "name": "Transmission"
        }
      }
    }
  },
  "id": "fooid",
  "name": "response",
  "namespace": "sysadm"
}

Changelog: yes

src/server/WebBackend.cpp

@@ -715,6 +715,7 @@ RestOutputStruct::ExitCode WebSocket::EvaluateSysadmIocageRequest(const QJsonVal
 	ok = true;
         out->insert("listjails", sysadm::Iocage::listReleases());
       }*/
+      else if(act=="listplugins"){  retObj = sysadm::Iocage::listPlugins(); }
       ok = !retObj.keys().isEmpty();
       if(ok){ out->insert(act,retObj); }
     } //end of "action" key usage