tests: posix: net: open native_sim in c++,posix,net,native case

Prior to the fixes in the previous commits, combining a build
for native_sim with

CONFIG_CPP=y
CONFIG_POSIX_API=y
CONFIG_STD_CPP20=y
CONFIG_REQUIRES_FULL_LIBCPP=y

would fail.

It succeeds now.

This change adds a testcase to monitor that scenario in CI.

Note: this was partially necessary because the deprecation of
CONFIG_NET_SOCKETS_POSIX_NAMES is not yet complete, so there
is a dependency cycle, and also because <sys/types.h> was
pulling in the host <sys/types.h> instead of Zephyr's or one
of the embedded OSes we support.

Signed-off-by: Chris Friedt <cfriedt@tenstorrent.com>
(cherry picked from commit d0808473)