Improve tracking of connectionless UDP syscalls

[Molter73]

Description

The recvmmsg and sendmmsg are used by passt in order to handle UDP messages. Because it does so in a stateless manner, we need to track these in order to support UDP on OCP Virt.

Checklist

• Investigated and inspected CI test results
• Updated documentation accordingly

Automated testing

• Added unit tests
• Added integration tests
• Added regression tests

If any of these don't apply, please comment below.

Testing Performed

Added relevant tests to CI.

[Molter73]

RHEL-SAP 8.4 is failing due to a verifier error on an unimplemented ebpf instruction. After some investigation, the instruction seems to be trying to load the address to the handle_exit function that needs to be called, (see this comment for more details on why it needs to be called). I'll look to see if it's possible to make falco skip a program that fails the verifier and keeps loading the rest of them, but for now I would like to disable the test unless we have a good reason to not do so.

[Molter73]

I have a potential fix for the RHEL-SAP 8.4 verifier issue on these 2 PRs:

• Only load interesting syscalls #1855
• Only load interesting syscalls falcosecurity-libs#84

Basically we can circumvent the verifier error by not loading the offending probe if collector is not configured to track send/recv syscalls.

I need to investigate why the TestUdpNetworkFlow suite is not being run, that one should still hit the verifier issue and will require it to be excluded from the tests run on RHEL-SAP 8.4.

[Stringy]

Couple of questions and comments, but overall LGTM!