Re-add supports_rename and rename to PathManager

Created by: andrewPoulton

Addresses #477 (closed), and also adds rename method to PathManager which is also called in checkpoint_utils.torch_persistent_save.

Currently untested, @Xirider should run in his env, as he found the bug.

metaseq/file_io/common/__init__.py

@@ -741,6 +741,18 @@ class PathManager:
                 return True
         return False
 
+    def supports_rename(self, path: str) -> bool:
+        # PathManager doesn't yet support renames
+        return not self.path_requires_pathmanager(path)
+
+    def rename(self, src: str, dst: str) -> None:
+        if self.supports_rename(src):
+            os.rename(src, dst)
+        else:
+            raise ValueError(
+                f"Path {src} requires PathHandler, and so doesn't support renaming."
+            )
+
     # pyre-fixme[24]: Generic type `os.PathLike` expects 1 type parameter.
     def __get_path_handler(self, path: Union[str, os.PathLike]) -> PathHandler:
         """