Return ChangeSet for undo and redo

main.py

@@ -84,15 +84,11 @@ async def fastapi_unlock_project(network: str):
 # undo/redo
 @app.post("/undo/")
 async def fastapi_undo(network: str):
-    execute_undo(network)
-    
-    return True
+    return execute_undo(network)
 
 @app.post("/redo/")
 async def fastapi_redo(network: str):
-    execute_redo(network)
-    
-    return True
+    return execute_redo(network)
 
 @app.get("/getcurrentoperationid/")
 async def fastapi_get_current_operaiton_id(network: str) -> int: