cp: fixing cp -a functionality to match gnu implementation for -z flag handling and for folders

[ChrisDryden]

This has been in the works for a few days where I have been adding the functionality that is expected by the gnu integration tests for cp, the main areas that were missing were related to skipping copying the selinux xattr's.

Theres a bit of overlap between this PR and this one: #10083 since they both cover how to skip those types of ENOSUP errors.

The only other change is that I added is that one of the utilities was needed to run this test on the SELINUX build.

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/cp/cp-a-selinux is no longer failing!

[sylvestre]

some jobs are failing

[codspeed-hq]

Merging this PR will degrade performance by 5.04%

⚡ 1 improved benchmark
❌ 2 regressed benchmarks
✅ 139 untouched benchmarks
⏩ 180 skipped benchmarks¹

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	split_number_chunks	285.8 µs	301 µs	-5.04%
❌	Simulation	split_bytes	515.4 µs	537.1 µs	-4.03%
⚡	Simulation	mv_force_overwrite	148 ms	142.4 ms	+3.96%

---

_{Comparing ChrisDryden:fix-cp-a-selinux-test (9298139) with main (6124866)}

Footnotes

1. 180 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/cp/cp-a-selinux is no longer failing!

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/tty/tty-eof (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/cp/cp-a-selinux is no longer failing!

[sylvestre]

sorry, it conflicts :(

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/cp/cp-a-selinux is no longer failing!

[sylvestre]

@ChrisDryden seems that it needs some love :)

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/tail/retry. tests/tail/retry is passing on 'main'. Maybe you have to rebase?
Congrats! The gnu test tests/cp/cp-a-selinux is no longer failing!