Add code to skip labels if LabelText is empty.

Backported from teksi tww https://github.com/teksi/wastewater/blob/3acfba249866d299f8a22e249d9f1e475fe7b88d/plugin/teksi_wastewater/interlis/interlis_model_mapping/interlis_exporter_to_intermediate_schema.py#L2667 and following

qgepqwat2ili/qgep/export.py

@@ -1090,6 +1090,15 @@ def textpos_common(row, t_type, geojson_crs_def):
             layer_name = label["properties"]["Layer"]
             obj_id = label["properties"]["qgep_obj_id"]
 
+            print(f"label[properties]: {label['properties']}")
+
+            if not label["properties"]["LabelText"]:
+                logger.warning(
+                    f"Label of object '{obj_id}' from layer '{layer_name}' is empty and will not be exported"
+                )
+                continue
+
+
             if layer_name == "vw_qgep_reach":
                 if obj_id not in tid_for_obj_id["haltung"]:
                     logger.warning(f"Label for haltung `{obj_id}` exists, but that object is not part of the export")