Enable the full TCP KeepAlive mechanism on Windows (#1568) #1532 implemented the full support of TCP Keep-Alives on UNIX-like OS's while leaving a `TODO` for Windows. This PR intends to resolve that `TODO`. ## References - [SIO_KEEPALIVE_VALS Control Code](https://learn.microsoft.com/en-us/windows/win32/winsock/sio-keepalive-vals) - [IPPROTO_TCP socket options](https://learn.microsoft.com/en-us/windows/win32/winsock/ipproto-tcp-socket-options) - [TCP_KEEPINVTL and TCP_KEEPIDLE - Socket Keep Alives not working](https://cygwin.com/pipermail/cygwin/2020-June/245436.html) - [Cygwin: tcp: Support TCP_KEEPIDLE, TCP_KEEPCNT, TCP_KEEPINTVL](https://sourceware.org/pipermail/cygwin-cvs/2020q3/014473.html) - [Add cross-platform support for keep-alive socket options](https://github.com/dotnet/corefx/pull/29963/files)