updatehub-clod-sdk: Improve object download speed
updatehub-clod-sdk: Improve object download speed

We now use async_std's `ReadExt` to make a buffered download instead of
streaming byte by byte

Signed-off-by: Jonathas-Conceicao <33cd5f63a6435f6b1365c76100ff4a5652c45928@ossystems.com.br>

UpdateHub/updatehub