ssl: Give correct errno value for "timed out" exceptions

[jepler]

Incorrect error handling in send/recv would raise an OSError with an incorrect (negative) code.

It's likely that this bug was always happening in the Pico W implementation, which became the basis of the current shared implementation.

Push handling of WANT_{READ,WRITE} down into mbedtls_raise_error and use it in recv_into and send.

Tested by connecting to google.com:443, sending nothing, and trying to read a byte:

import socketpool, ssl, time, wifi
socket = socketpool.SocketPool(wifi.radio)
ctx = ssl.SSLContext()
with ctx.wrap_socket(socket.socket()) as ss:
    ss.connect(("google.com", 443))
    ss.settimeout(1)
    b = bytearray(1)
    try:
        t0 = time.monotonic()
        ss.recv_into(b)
    except Exception as ee:
        t1 = time.monotonic()
        exc = ee
        print(t1-t0)
        raise exc

As desired, an exception OSError: [Errno 116] ETIMEDOUT occurred and the time delta value was 1.0 seconds.

(tested on pycamera)

Closes: #8988

[dhalbert]

Thanks!

[dhalbert]

@justmobilize want to test?

[justmobilize]

@dhalbert - tested on both a Pico W and UM FeatherS3. Works great!