[FIX] http: rewind file upload on serialization failure

Before this commit:
When uploading a file, if the transaction fails due to a serialization
failure, Odoo will retry the request. However, if a file upload is read
during the transaction, the file pointer will be at the end of the file,
and calling `.read()` again returns an empty bytes object.

After this commit:
Upon retrying the request, rewind uploads to the beginning of the file,
if the file supports it.

opw-3228200

closes odoo/odoo#117669

Signed-off-by: Julien Castiaux (juc) <juc@odoo.com>