DAOS-19492 duns: wait for UNS entry point resolution in duns_create_path

[mchaarawi]

duns_create_path, which does need the invalidation's effect before
returning, now polls until the path is confirmed bound to the
new container before returning success.

Test-tag: DfuseContainerAttrs
Quick-Functional: true
Test-repeat: 10

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).

[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-18879/1/testReport/

[github-actions]

Ticket title is 'dfuse/container_attrs.py:DfuseContainerAttrs.test_dfuse_subcontainer_create_attrs - Unexpected number setting(s) of attribute dfuse-attr-time: want=1, got=0'
Status is 'In Progress'
Labels: 'ci_master_daily'
Errors are Unknown component
https://daosio.atlassian.net/browse/DAOS-19492

[daosbuild3]

Test stage Build on EL 9 completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-18879/2/execution/node/512/log

[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-18879/3/testReport/