Add support for setting TCP ACK Frequency on Windows

[derek-will]

Windows supports configuring the number of TCP segments which must be received before the delayed ACK timer is ignored on a per socket basis. This is an especially useful feature when interacting with TCP servers in low-latency, small messaging scenarios. Windows does not officially support the TCP_QUICKACK socket option, but does define SIO_TCP_SET_ACK_FREQUENCY in mstcpip.h which can be used to achieve a similar objective albeit on a permanent basis.

I've made the proposed code changes here. Seeking to obtain consensus that the feature is a good addition to socket2 and the proposed design is the right one per the contributing guidelines. I will open a pull request if the feature is accepted and when the design is finalized per the aforementioned contribution guidelines. Thank you for your time!

Related: https://learn.microsoft.com/en-us/troubleshoot/windows-server/networking/registry-entry-control-tcp-acknowledgment-behavior
Example: https://stackoverflow.com/questions/55034112/c-disable-delayed-ack-on-windows

[Darksonn]

Said paragraph in the contributing guidelines is to avoid wasting your time on implementation if the feature is declined. Since you have already taken the time to write up an implementation, you can open a PR right away.