feat(xattr): attribute_display for linux compatibility

[pineapplehunter]

This will add custom formatting to "security.capability" attribute.
Adds capctl as a dependency only for Linux.

I’m new to this code base, so please let me know if there’s anything I should adjust or improve.

fixes #1219

Here is a comparison of the output of ping on ubuntu.
Before:

.rwxr-xr-x@   90k root 25/07/24 20:51 󰡯 /usr/bin/ping
                                      └── security.capability: "\u{1}\0\0\u{2}\0 "

After:

.rwxr-xr-x@  90k root 25/07/24 20:51 󰡯 /usr/bin/ping
                                     └── security.capability: <cap_net_raw=ep>

[pineapplehunter]

I did a rebase, and the tests are failing now.
I do not think the tests are failing because of my changes, but let me know if I need to change something.