Improve the action schema.

The new schema is functionally equivalent to the old schema
but the non-validation messages are much better.

Validating

{"action": "failed_task", "message": "It's going well!"}

against the old schema may yield (it is not deterministic)

action['worker'] is missing and action['worker'] is missing and
action['worker'] is missing and action['action']
(value:'failed_task') is not equal to 'system_event' and
action['action'] (value:'failed_task') is not equal to 'new_run'
and action['action'] (value:'failed_task') is not equal to
'upload_nn' and action['action'] (value:'failed_task') is not
equal to 'modify_run' and action['action'] (value:'failed_task')
is not equal to 'delete_run' and action['action']
(value:'failed_task') is not equal to 'stop_run' and
action['action'] (value:'failed_task') is not equal to
'finished_run' and action['action'] (value:'failed_task') is not
equal to 'approve_run' and action['action'] (value:'failed_task')
is not equal to 'purge_run' and action['user'] is missing and
action['user'] is missing and action['worker'] is missing and
action['action'] (value:'failed_task') is not equal to
'log_message'

whereas the new schema gives

action['worker'] is missing

Requires upgrading the vtjson package.

server/fishtest/actiondb.py

@@ -218,8 +218,10 @@ def insert_action(self, **action):
         action["time"] = datetime.now(timezone.utc).timestamp()
         try:
             validate(action_schema, action, "action")
-        except ValidationError:
-            message = f"Internal Error. Request {str(action)} does not validate"
+        except ValidationError as e:
+            message = (
+                f"Internal Error. Request {str(action)} does not validate: {str(e)}"
+            )
             print(message, flush=True)
             self.log_message(
                 username="fishtest.system",