DAOS-18634 control: Fix container query for non-POSIX

[tanabarr]

In dmg container query workflow, remove recursive loop when trying to
print ObjectClass and avoid attempting to print POSIX container fields
if no embedded struct pointer exists. This fixes segfault when running
contain a query on a non-POSIX container. Add missing unit test
coverage for cmd/daos/pretty/container.go PrintContainers() and
PrintContainerInfo().

Features: control

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 'daos container query p0 c1: panic: runtime error: invalid memory address or nil pointer dereference'
Status is 'In Review'
https://daosio.atlassian.net/browse/DAOS-18634

[daosbuild3]

Test stage Unit Test on EL 8.8 completed with status UNSTABLE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net/job/daos-stack/job/daos//view/change-requests/job/PR-17673/1/testReport/

[daosbuild3]

Test stage NLT on EL 8.8 completed with status UNSTABLE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net/job/daos-stack/job/daos//view/change-requests/job/PR-17673/1/testReport/

[daosbuild3]

Test stage Functional Hardware Medium MD on SSD completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-17673/1/execution/node/1364/log