DAOS-17523 dfs: Show dir/file object classes correctly

[onever23]

client/dfs/mnt/dfs_query() updated to lookup file and directory object classes if default attributes fields are 0

• backported to 2.8 release

Signed-off-by: Oleg Neverovitch oleg.neverovitch@hpe.com

Steps for the author:

• Commit message follows the guidelines.
• Appropriate Features or Test-tag pragmas were used.
• Appropriate Functional Test Stages were run.
• At least two positive code reviews including at least one code owner from each category referenced in the PR.
• Testing is complete. If necessary, forced-landing label added and a reason added in a comment.

After all prior steps are complete:

• Gatekeeper requested (daos-gatekeeper added as a reviewer).

[github-actions]

Ticket title is 'Default file and directory object class is UNKNOWN in cont query for rd_fac 2 on aurora'
Status is 'Awaiting backport'
Labels: 'ALCF,alcf_prod,easy'
Job should run at elevated priority (1)
https://daosio.atlassian.net/browse/DAOS-17523

[daosbuild3]

Test stage Functional on EL 9 completed with status UNSTABLE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net/job/daos-stack/job/daos//view/change-requests/job/PR-17951/5/testReport/