Add default dim to cat (similar to torch.cat) (#521)

Author: rusty1s

torch_frame/utils/concat.py

@@ -31,7 +31,7 @@
 
 def cat(
     lst: list[T],
-    dim: int,
+    dim: int = 0,
 ) -> T:
     r"""Concatenates a list of :class:`TensorFrame` or :class:`TensorData`.