selftests/bpf: Expand sockaddr program return value tests

This patch expands verifier coverage for program return values to cover
bind, connect, sendmsg, getsockname, and getpeername hooks. It also
rounds out the recvmsg coverage by adding test cases for recvmsg_unix
hooks.

Signed-off-by: Jordan Rife <jrife@google.com>
Link: https://lore.kernel.org/r/20240510190246.3247730-15-jrife@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Migrate recvmsg* return code tests to verifier_sock_addr.c

This set of tests check that the BPF verifier rejects programs with
invalid return codes (recvmsg4 and recvmsg6 hooks can only return 1).
This patch replaces the tests in test_sock_addr.c with
verifier_sock_addr.c, a new verifier prog_tests for sockaddr hooks, in a
step towards fully retiring test_sock_addr.c.

Signed-off-by: Jordan Rife <jrife@google.com>
Link: https://lore.kernel.org/r/20240510190246.3247730-2-jrife@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>