Draft: smbdirect: Add testing infrastructure and test smbdirect in CI

This builds upon MR4343 and thus contains all patches from that merge request. It would not make sense to just add the smbdirect_ko_wrapper alone. It also depends on some minor support in socket_wrapper, which must be merged first.

smbdirect_ko_wrapper builds upon the linux syscalls process_vm_writev and process_vm_readv.