[lldb/test] Test lldb-server named pipe functionality on windows

lldb-server can use a named pipe to communicate the port number it is
listening on. This windows bits of this are already implemented, but we
did not have a test for that, most likely because python does not have
native pipe functionality.

This patch implements the windows bits necessary to test this. I'm using
the ctypes package to call the native APIs directly to avoid a
dependency to non-standard python packages. This introduces some amount
of boilerplate, but our named pipe use case is fairly limited, so we
should not end up needing to wrap large chunks of windows APIs.

Surprisingly to changes to lldb-server were needed to make the test
pass.

Differential Revision: https://reviews.llvm.org/D96260