Hash table charts

[thiagoftsm]

Summary

This PR is adding monitoring information for elements inside hash tables.

This PR is actually completely blocked by #15214

Test Plan

1. Compile this Branch
2. Enable threads inside your /etc/netdata/ebpf.d.conf and also enable integration with apps

[global]
    apps = yes
    collect pid = all
[ebpf programs]
    cachestat = yes
    dcstat = yes
    fd = yes
    oomkill = yes
    process = yes
    shm = yes
    socket = yes
    swap = yes
    vfs = yes

3. Start netdata
4. Wait few second and take a look on chart, or query:

$ curl -o insert.txt "http://localhost:19999/api/v1/data?chart=netdata.ebpf_hash_tables_insert_pid_elements&after=-300"
$ curl -o remove.txt "http://localhost:19999/api/v1/data?chart=netdata.ebpf_hash_tables_remove_pid_elements&after=-300"

5. Test if you do not have any libbpf issue (We still can have for some distributions like Gentoo):

$ grep libbpf /var/log/netdata/* > logs.txt

Additional Information

This PR was tested on:

Distribution	Host	kernel	inserted	removed	libbpf errors
Slackware Current	Bare metal	6.1.38	slackware_6_1_insert.txt	slackware_6_1_remove.txt	slackware_6_1_logs.txt
Arch Linux	Libvirtt	6.4.3-arch1-1	arch_6_4_insert.txt	arch_6_4_remove.txt	arch_6_4_logs.txt
Ubuntu 22.04	Libvirt	5.15.0-76-generic	ubuntu_5_15_insert.txt	ubuntu_5_15_remove.txt	ubuntu_5_15_logs.txt
Debian 11	libvirt	5.10.0-23-amd64	debian_5_10_insert.txt	debian_5_10_remove.txt	debian_5_10_logs.txt
Alma 9	libvir	5.14.0-284.11.1.el9_2.x86_64	alma_5_14_insert.txt	alma_5_14_logs.txt	alma_5_14_remove.txt
Ubuntu 20.04	libvirt	5.4.0-146-generic	ubuntu_5_4_insert.txt	ubuntu_5_4_remove.txt	ubuntu_5_4_logs.txt
Ubuntu 18.04	libvirt	4.15.0-208-generic	ubuntu_4_15_insert.txt	ubuntu_4_15_remove.txt	ubuntu_4_15_logs.txt
Slackware current	Qemu	4.14.290	slackware_4_14_insert.txt	slackware_4_14_remove.txt	slackware_4_14_logs.txt
CentOS 7.9	libvirt	3.10.0-1160.92.1.el7.x86_64	centos_3_10_insert.txt	centos_3_10_remove.txt	centos_3_10_logs.txt

For users: How does this change affect me?

Describe the PR affects users: - Which area of Netdata is affected by the change? eBPF plugin - Can they see the change or is it an under the hood? If they can see it, where? They will have more charts in netdata monitoring section - How is the user impacted by the change? eBPF.plugin will store more data inside hash table. - What are there any benefits of the change? A better understanding about what is happening in your host.

[MrZammler]

Tested on an Debian VM, appears to work fine! I have the charts ok!

[underhood]

I did only quick basic testing on this one. Approving to unblock (if you need deeper review ignore this approval)