roll up of fixes in junos action plugin (#21624)

* calls open_shell() or open_session() depending on connection type
* closes shell after module completion
* adds open_session() to netconf

lib/ansible/plugins/connection/netconf.py

@@ -101,6 +101,9 @@ class Connection(ConnectionBase):
     def exec_command(self, request):
         """Sends the request to the node and returns the reply
         """
+        if request == 'open_session()':
+            return (0, 'ok', '')
+
         req = to_ele(request)
         if req is None:
             return (1, '', 'unable to parse request')