bpo-31806: Use _PyTime_ROUND_TIMEOUT for the timeout argument parsing in more functio...

bpo-31806: Use _PyTime_ROUND_TIMEOUT for the timeout argument parsing in more functions (#4026)

Fix timeout rounding in time.sleep(), threading.Lock.acquire() and
socket.socket.settimeout() to round correctly negative timeouts between -1.0 and
0.0. The functions now block waiting for events as expected. Previously, the
call was incorrectly non-blocking.