Support container

[keisku]

Add a new feature that can start monitoring by container name or container id.

u64 get_task_cgroup_id(struct task_struct *task)
{
    struct css_set *cgroups;
    u64 cgroup_id;
    bpf_rcu_read_lock();
    cgroups = task->cgroups;
    cgroup_id = cgroups->dfl_cgrp->kn->id;
    bpf_rcu_read_unlock();
    return cgroup_id;
}