[Bug] Users can submit socket events that are not intended for them
**Describe the bug**
There are two socket events (`on_node_info_update` and  `on_algorithm_status_change`) that are intended for nodes but which a user connected to a socket event could also access. They can't really use these to do anything harmful, but it should not be possible nevertheless.

diff --git a/vantage6-server/vantage6/server/websockets.py b/vantage6-server/vantage6/server/websockets.py
index 2b2328aa..4ef38785 100644
--- a/vantage6-server/vantage6/server/websockets.py
+++ b/vantage6-server/vantage6/server/websockets.py
@@ -227,6 +227,12 @@ class DefaultSocketNamespace(Namespace):
                 "collaboration_id": 1
             }
         """
+        # only allow nodes to send this event
+        if session.type != 'node':
+            self.log.warn('Only nodes can send algorithm status changes! '
+                          f'{session.type} {session.auth_id} is not allowed.')
+            return
+
         result_id = data.get('result_id')
         task_id = data.get('task_id')
         collaboration_id = data.get('collaboration_id')
@@ -272,6 +278,12 @@ class DefaultSocketNamespace(Namespace):
         node_config: dict
             Dictionary containing the node's configuration.
         """
+        # only allow nodes to send this event
+        if session.type != 'node':
+            self.log.warn('Only nodes can send node configuration updates! '
+                          f'{session.type} {session.auth_id} is not allowed.')
+            return
+
         node = db.Node.get(session.auth_id)
 
         # delete any old data that may be present (if cleanup on disconnect
['vantage6-server/vantage6/server/websockets.py']