selftests/bpf: Move IPv4 and IPv6 sockaddr test cases

selftests/bpf: Move IPv4 and IPv6 sockaddr test cases

This patch lays the groundwork for testing IPv4 and IPv6 sockaddr hooks
and their interaction with both socket syscalls and kernel functions
(e.g. kernel_connect, kernel_bind, etc.). It moves some of the test
cases from the old-style bpf/test_sock_addr.c self test into the
sock_addr prog_test in a step towards fully retiring
bpf/test_sock_addr.c. We will expand the test dimensions in the
sock_addr prog_test in a later patch series in order to migrate the
remaining test cases.

Signed-off-by: Jordan Rife <jrife@google.com>
Link: https://lore.kernel.org/r/20240429214529.2644801-5-jrife@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>