Feature Request: Add upsert / overwrite support to storage.move()

[KiddoV]

It would be useful if storage.move() supported overwriting the destination file, similar to upload().

Current behavior:

await storage.move(
  "avatar_temp.jpg",
  "avatar.jpg",
);

If avatar.jpg already exists, the move fails with a duplicate error. The current workaround is:

await storage.remove(["avatar.jpg"]);
await storage.move("avatar_temp.jpg", "avatar.jpg");

Proposed API:

await storage.move(
  "avatar_temp.jpg",
  "avatar.jpg",
  fileOptions: const FileOptions(upsert: true),
);

or

await storage.move(
  "avatar_temp.jpg",
  "avatar.jpg",
  overwrite: true,
);

This would make move() consistent with upload(), reduce API calls, and simplify common file replacement workflows.