I'm not sure it works, but it's enough code-wise for now. We're reusing some
http-gw components here that are to be moved into sdk-go in future.
Signed-off-by: Roman Khimov <roman@nspcc.ru>
Mostly taken from old SDK (abe47687cd11266f946cad57f07572cc10c67226), but
error handling adapted to eliminate pkg/errors and internal packages.
Signed-off-by: Roman Khimov <roman@nspcc.ru>