Viosock: Take Care of Recv Requests Stucks After Socket Shutdown

[MartinDrab]

When an other end (peer) of the socket reports a shutdown, the recv request queue is not processed. This means that some recv calls may get stuck forever. This pull request changes the behavior -- when a shutdown from its peer is received, the recv queue gets processed and all requests that would get stuck are completed with STATUS_SUCCESS (which usually ends in receiving zero bytes).

This should fix #1020. I tested with

• client in WIndows VM, server on the host,
• • both client and server within the same Windows VM.

[YanVugenfirer]

@MartinDrab Thanks! Waiting for CI to run before merging