add cassandra trace

[anngdinh]

Hi teams, I just add trace for Cassandra protocol, it still have some issue: when Cassandra response the id of prepare statement (in eBPF tracepoint), it's not have fixed length like MySQL, i don't know how to pass it to l7_events and sent to user space and not make the body size bigger (may impact the performance). I just get 4 first byte of the id (it's still work for me) but it's just a temporary solution. Thank you.

[apetruhin]

@anngdinh, We will review this a bit later, perhaps next week. Thank you.