[webhook] New, very simple binding for listening incomming http requests

Here is my thing configuration (replace the xxxxxxxxxx with your thingId)

UID: httplistener:HttpListener:xxxxxxxxxx
label: Doorbell Webhook
thingTypeUID: httplistener:HttpListener
configuration:
  jsonConfig: |-
    {
      "channels": [
        {
          "key":"user_id",
          "kind": "STATE",
          "state": "req.body.json.user_id"
        },
        {
          "key":"event_type",
          "kind": "STATE",
          "state": "req.body.json.event_type"
        },
        {
          "key":"device_id",
          "kind": "STATE",
          "state": "req.body.json.device_id"
        },
        {
          "key":"home_id",
          "kind": "STATE",
          "state": "req.body.json.home_id"
        },
        {
          "key":"home_name",
          "kind": "STATE",
          "state": "req.body.json.home_name"
        },
        {
          "key":"camera_id",
          "kind": "STATE",
          "state": "req.body.json.camera_id"
        },
        {
          "key":"event_id",
          "kind": "STATE",
          "state": "req.body.json.event_id"
        },
        {
          "key":"subevent_id",
          "kind": "STATE",
          "state": "req.body.json.subevent_id"
        },
        {
          "key":"snapshot_url",
          "kind": "STATE",
          "state": "req.body.json.snapshot_url"
        },
        {
          "key":"vignette_url",
          "kind": "STATE",
          "state": "req.body.json.vignette_url"
        },
        {
          "key":"session_id",
          "kind": "STATE",
          "state": "req.body.json.session_id"
        },
    	{
          "key":"push_type",
          "kind": "STATE",
          "state": "req.body.json.push_type"
        }
      ]
    }

Then I defined on https://dev.netatmo.com an app.
Set Redirect URI & Webhook URI to (also defined a port forwarding listen_port_webhook → openhab_external_listen_port on my router):

https://my_external_url:listen_port_webhook/httplistener/xxxxxxxxxx)

Additionally I had to configure the nginx proxy:

        location = /httplistener/xxxxxxxxxx {
                auth_basic          off;
                proxy_pass          https://internal_openhab_uri:https_internal_openhab_port/httplistener/xxxxxxxxxx;
        }