Decode syscalls arguments

[yanivagman]

We alreaady decode some of the syscall arguments (see #493), but there are stil some syscall arguments for which we don't decode the argument values although it can be useful.

• [ ] nstype for setns syscall
• [ ] cap_user_data_t for capset syscall
• [x] struct timespec for nanosleep and some other syscalls More...

[itaysk]

also https://github.com/aquasecurity/tracee/issues/453

[yanivagman]

Closing in favor of #2336