Merge PR #28560 into master

* refs/pull/28560/head:
	cephfs-shell: handle du's arguments elsewhere outside do_du()
	cephfs-shell: reuse code
	cephfs-shell: rewrite call to perror in do_du
	pybind/cephfs: define variable for hexcode used in stat()
	test_cephfs_shell: test cephfs-shell command at invocation
	cephfs-shell: refactor do_du()
	cephfs-shell: option -r is not for reverse
	cephfs-shell: extend to_bytes()
	test_cephfs_shell: test du with no args
	test_cephfs_shell: test du with multiple paths in args
	test_cephfs_shell: test behaviour of "du -r"
	test_cephfs_shell: test du's output for softlinks
	qa/cephfs: add convenience method lstat()
	qa/cephfs: add option to make stat() unfollow symlinks
	test_cephfs_shell: test du's output for hardlinks
	test_cephfs_shell: test du's output for directories
	test_cephfs_shell: test du's output for regular files
	test_cephfs_shell: add a method to get command output
	test_cephfs_shell: allow cmd as list too
	test_cephfs_shell: rename and rewrite _cephfs_shell()
	test_cephfs_shell: copy humanize() from cephfs-shell
	cephfs-shell: print disk usage for non-directory files too
	pybind/cephfs: add method that stats symlinks without following
	cephfs-shell: Fix 'du' command error

Reviewed-by: Varsha Rao <varao@redhat.com>
Reviewed-by: Patrick Donnelly <pdonnell@redhat.com>