Add support about Content-Disposition in QuerySignHTTPReadWithContext

Can you support the Header parameter Content-Disposition

Make sense.

We will add Content-Disposition in read, and query_sign_http_read will have it too.

ping @go-storage-maintainer for a look. It should be a global pair, need a proposal.

@jiaming-he Do you want to implement the feature once we have drafted the proposal? It should be a easy and one line change, suitable for new contributors.

Yes, the proposal is required.