Fixed#779#791
- Retry request on timeout
- Retry for `StatusCode::{REQUEST_TIMEOUT, GATEWAY_TIMEOUT}`
- Add `DEFAULT_RETRY_DURATION_FOR_RATE_LIMIT` for 503/429
if 503/429 does not give us a header or give us an invalid header on
when to retry, we would default to
`DEFAULT_RETRY_DURATION_FOR_RATE_LIMIT`.
- Fix `Client::get_redirected_final_url`: Retry using `GET` on status code 400..405 + 410
- Rename remote_exists => remote_gettable & support fallback to GET
if HEAD fails due to status code 400..405 + 410.
- Improve `Client::get_stream`: Include url & method in the err of the stream returned
Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>
