[OMCProcessDockerHelper] add get_docker_container_id()

Author: syntron

OMPython/OMCSession.py

@@ -649,6 +649,12 @@ def serverAdress(self) -> Optional[str]:
 
         return None
 
+    def get_docker_container_id(self) -> str:
+        if not isinstance(self._dockerCid, str):
+            raise OMCSessionException(f"Invalid docker container ID: {self._dockerCid}!")
+
+        return self._dockerCid
+
 
 class OMCProcessDocker(OMCProcess, OMCProcessDockerHelper):