debugfs: decode and dump xattrs on inode stat

debugfs: decode and dump xattrs on inode stat

Decode and print Access Control Lists in debugfs stat/ea_list.

Print the Lustre "fid", "lma", and "link" xattr contents,
if present, with "debugfs stat" to simplify debugging.
Add "layout_version" and "range" values when printing a
trusted.fid xattr.

Increase the size of xattrs hex-dumped from 40 to 120.  But as
Lustre encrypted inodes may contain illegal characters in their
names, it is also needed to escape non-printable characters in
linkEA.

Change-Id: I3ee35ddb02582ab66d4e25ff76fae35935b54508
Reviewed-on: https://review.whamcloud.com/43384
Reviewed-by: Li Dongyang <dongyangli@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>