Object payload transferred in chunks. Size of the
chunks may be limited by transport protocols. To
split it we use `io.CopyBuffer` with pre-allocated
buffer size of one chunk. However this function may
ignore buffer if reader or writer implements
`WriteTo` or `ReadFrom` methods. Unfortunately
`bytes.Reader` implements `WriteTo` function.
To fix this we wrap reader so wrapper implements
only `io.Reader` interface.
Related to github.com/nspcc-dev/neofs-node/issues/338
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
9401724b9c