[OMCSessionZMQ] allways check for errors if using sendExpression()

needs the preparation / additional changes in OMCSession* and ModelicaSystem

Author: syntron

OMPython/OMCSession.py

@@ -546,6 +546,17 @@ def sendExpression(self, command, parsed=True):
             return None
         else:
             result = self._omc.recv_string()
+
+            # allways check for error
+            self._omc.send_string("getErrorString()", flags=zmq.NOBLOCK)
+            error_raw = self._omc.recv_string()
+            error_str = om_parser_typed(error_raw)
+            if error_str:
+                if "Error" in error_str:
+                    raise OMCSessionException(f"OM Error for 'sendExpression({command}, {parsed})': {error_str}")
+                else:
+                    logger.warning(f"[OM]: {error_str}")
+
             if parsed is True:
                 try:
                     return om_parser_typed(result)