LU-10499 pcc: Check if PCC copy is unlinked for state output

LU-10499 pcc: Check if PCC copy is unlinked for state output

In this patch, it adds support for the command "lfs pcc state" to
check whether the PCC copy is in the local client cache or
unlinked improperly.

Do not print an error message if "lfs pcc detach" tries to detach
a file that is already removed from the cache.  This might happen
for a wide variety of reasons (external cache cleanup process, etc).

EX-bug-id: EX-3825
Test-Parameters: testlist=sanity-pcc env=ONLY=48
Signed-off-by: Qian Yingjin <qian@ddn.com>
Change-Id: Ic50c901df78adfaf5b56990120f832e5d74a117c
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/54451
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Li Xi <lixi@ddn.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>