[#NETCONF-499] Support for Root Resource Discovery is missing

Both RFC8040 [0] and draft 18 [1] define Root Resource Discovery mechanism. Neither Draft18 in Nitrogen snapshots, not rfc8040 in oxygen snapshots seem to have that implemented.

$ curl -v -u admin:admin -H "Accept:application/xrd+xml" http://127.0.0.1:8181/.well-known/host-meta

*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to 127.0.0.1 (127.0.0.1) port 8181 (#0)
* Server auth using Basic with user 'admin'
> GET /.well-known/host-meta HTTP/1.1
> Host: 127.0.0.1:8181
> Authorization: Basic YWRtaW46YWRtaW4=
> User-Agent: curl/7.52.1
> Accept:application/xrd+xml
>
< HTTP/1.1 404 Not Found
< Content-Type: text/html; charset=ISO-8859-1
< Cache-Control: must-revalidate,no-cache,no-store
< Content-Length: 305
<
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title>Error 404 Not Found</title>
</head>
<body><h2>HTTP ERROR 404</h2>
<p>Problem accessing /.well-known/host-meta. Reason:
<pre>    Not Found</pre></p><hr><i><small>Powered by Jetty://</small></i><hr/>

</body>
</html>
* Curl_http_done: called premature == 0
* Connection #0 to host 127.0.0.1 left intact

[NETCONF-499] Support for Root Resource Discovery is missing Created: 16/Jan/18 Updated: 10/Feb/21 Resolved: 18/Dec/20
Status:	Resolved
Project:	netconf
Component/s:	restconf-nb
Affects Version/s:	None
Fix Version/s:	1.13.0, Aluminium SR2

[NETCONF-499] Support for Root Resource Discovery is missing Created: 16/Jan/18 Updated: 10/Feb/21 Resolved: 18/Dec/20