add probe bof

[rwhitcroft]

Test if a remote port is open, similar to nc -z.

Issues:

• I defined struct addrinfo directly in bofdefs.h, but not sure this is allowed. I did this because including <ws2tcpip.h> results in warnings from other bofs that include <windows.h> before bofdefs.h.
• I don't have a CS license, so I'm using Sliver for all of this. I can't test the SA.cna part but tried to copy the other ones.

I realize this is not a groundbreaking addition to the repo, so no big deal if it's too much of a hassle to add. I had a blast learning BOF stuff either way.

[server] sliver (ALTERNATIVE_STAMINA) > probe 127.0.0.1 445

[*] Successfully executed probe (coff-loader)
[*] Got output:
127.0.0.1:445 OPEN

[server] sliver (ALTERNATIVE_STAMINA) > probe 127.0.0.1 12345

[*] Successfully executed probe (coff-loader)
[*] Got output:
127.0.0.1:12345 FAILED

[server] sliver (ALTERNATIVE_STAMINA) > probe dc01.ad.local 445

[*] Successfully executed probe (coff-loader)
[*] Got output:
dc01.ad.local:445 OPEN

[freefirex]

I'll be happy to review this and work with you on getting it merged in 😄

Just to let you know timeline I'm teaching this week, so I'll review and provide any feedback monday or tuesday of next week.

[rwhitcroft]

Thank you for the review and suggestions! I think I got them all fixed.

[freefirex]

Thanks for making those changes! merged