Add junos_system declartive module and other related change (#25859)

* Add junos_system declartive module and other related change

*  junos_system declartive module
*  integration test for junos_system
*  integration test for net_system (junos platform)
*  pep8 fixes for junos modules
*  move to lxml from elementree for xml parsing as it support
   complete set of xpath api's
*  other minor changes

* Fix CI and doc changes

* Fix unit test failures

* Fix typo in import

* Fix import issue for py2.6

* Add missed Element in import

lib/ansible/utils/jsonrpc.py

@@ -65,7 +65,6 @@ class Rpc:
         else:
             try:
                 result = rpc_method(*args, **kwargs)
-                display.display(" -- result -- %s" % result, log_only=True)
             except Exception as exc:
                 display.display(traceback.format_exc(), log_only=True)
                 error = self.internal_error(data=to_text(exc, errors='surrogate_then_replace'))
@@ -78,7 +77,6 @@ class Rpc:
 
                 response = json.dumps(response)
 
-        display.display(" -- response -- %s" % response, log_only=True)
         delattr(self, '_identifier')
         return response