Describe the bug
When running the OPC-UA Connector in ThingsBoard Gateway, an error occurs due to an unsupported operation between NoneType and str. The error originates from the _find_nodes function when attempting to concatenate a NoneType value with a string. This issue started occurring in version 3.7.0, whereas previous versions did not have this problem.

Recent changes in version 3.7.0, particularly in the _find_nodes function within opcua_connector.py, may have introduced scenarios where child_node.Name can be None, leading to this error. Reviewing the changes between versions 3.6.3 and 3.7.0 suggests that handling of child_node.Name was modified, potentially omitting necessary checks for None values.

Connector name (If bug in the some connector):
OPC-UA Connector

Error traceback (If available):

TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'
2025-02-18 13:25:34 - INFO  - [opcua_connector.py] - opcua_connector - _find_nodes - 504 - Found node: admin
2025-02-18 13:25:34 - ERROR - [tb_logger.py] - tb_logger - exception - 185 - unsupported operand type(s) for +: 'NoneType' and 'str'
Traceback (most recent call last):
  File "/thingsboard_gateway/connectors/opcua/opcua_connector.py", line 674, in _load_devices_nodes
  File "/thingsboard_gateway/connectors/opcua/opcua_connector.py", line 537, in find_node_name_space_index
    return await self.find_nodes(unresolved, current_parent_node=parent_node, nodes=resolved)
  File "/thingsboard_gateway/connectors/opcua/opcua_connector.py", line 510, in _find_nodes
    path_path + '.' + f'{child_node.Name}')

Versions (please complete the following information):

• OS: Docker
• ThingsBoard IoT Gateway version: 3.7.0