Socket management: fix management of `send` when partial sending done (no blocking sending error case)
Description
Current socket primitive adaptation code is considering that all bytes are sent in one call and in other cases the "would block" error will be raised event if partial sending was made.
But send
specification (windows / POSIX) does indicate that a partial sending could be made and in this case no "would block" error will be returned.
Note: the POSIX version does not indicates if the it is possible that it returns 0 bytes written (when there was more than 0 to write) whereas the Windows version specifies it:
If no buffer space is available within the transport system to hold the data to be transmitted, send will block unless the socket has been placed in nonblocking mode. On nonblocking stream oriented sockets, the number of bytes written can be between 1 and the requested length, depending on buffer availability on both the client and server computers.