CPython only supports the server_hostname keyword arg via the SSLContext
object, so use that instead of the top-level ssl.wrap_socket. This allows
the test to run on CPython the same as uPy.
Also add the "Host:" header to correctly make a GET request (for URLs that
are hosted on other servers). This is not strictly needed to test the SSL
connection but helps to debug things when printing the response.
This attempts to bootstrap network tests for MicroPython. This commits
sets test/net_inet/ as place for tests which require access to wide
Internet. They aren't intended to be run as part of the main testsuite,
instead to be run manually on demand.
test_tls_sites.py in particular check that it's possible to establish
SSL/TLS connection to select sites on the Internet: few references ones,
plus those for which problems were reported, and resolved.
