SIENTIAPDE-1312

Refactor OpcManager connection error handling and enhance unit tests

- Simplified error handling during connection attempts in OpcManager by removing redundant disconnection logic.
- Updated unit tests to include subscription_period_ms in server configuration and adjusted connection assertions to include a timeout parameter.
- Added new tests for disconnection fallback functionality to ensure robust error handling during disconnect attempts.

ingestor/managers/opc_manager.py

@@ -210,19 +210,8 @@ class OpcManager(BaseActivity):
             ).set(1)
             self.logger.info(f'Connection to {self.name} successful.')
         except Exception as e:
-            try:
-                await self.disconnect()
-            except Exception as internal_e:
-                self.logger.error(f'And error occurred while creating connection from {self.name}, and an exception occurred while disconnecting: {internal_e}')
+            await self.disconnect()
 
-            del self.client
-            self.client = None
-
-            metrics.OPC_CONNECTION_STATUS.labels(
-                pod_id=self.pod_id, server_name=self.name, server_url=self.url
-            ).set(0)
-            metrics.OPC_CONNECTIONS_FAILED.labels(pod_id=self.pod_id, server_name=self.name).inc()
-            self.logger.error(f'Failed to connect to {self.name}: {e}')
             raise
 
     async def create_subscription(self, name: str):