Fixed#747
- Add dep compact_str v0.6.1 to binstalk-downloader
- Impl new type `DelayRequest`
- Handle 503/429 with wait duration > `MAX_RETRY_DURATION` by simply taking the min
- Fix `Client::send_request_inner`: Ensure 503/429 get propagated to other requests
even if the current requests reach its maximum retry and decides to
simply return an error.
Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>