Gmoshkin/fix socket double close

Summary

• feat: UnsafeSendSyncTcpStream hack

• fix: used to close tcp socket twice

• test: add a test for tcp stream double close

• refactor: reuse a single buffer in network client receiver

• refactor: non-joinable iproto client worker fibers

• fix: fiber::Builder::start_non_joinable always return id

Ensure that

• New code is covered by tests
• API is documented
• Changelog is up to date
• Version is bumped in the appropriate Cargo.toml files