Extend sched_process_fork with scheduling fields

Extend sched_process_fork with scheduling fields

Add the scheduling policy informations of the newly created process:
- nice
- rt_priority,
- dl_runtime,
- dl_deadline,
- dl_period

Here is an example output:
sched_process_fork: { cpu_id = 4 }, { parent_comm = "bash", parent_tid =
17942, parent_pid = 17942, parent_ns_inum = 4026531836, child_comm =
"bash", child_tid = 10005, _vtids_length = 1, vtids = [ [0] = 10005 ],
child_pid = 10005, child_ns_inum = 4026531836, prio = 20, policy = (
"SCHED_NORMAL" : container = 0 ), nice = 0, rt_priority = 0, dl_runtime
= 0, dl_deadline = 0, dl_period = 0 }

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>