DAOS-19636 object: fix client layout refresh races

[gnailzenh]

Layout refresh during rebuild or reintegration can invalidate physical shard indices between selection, target preparation, and RPC dispatch. Protect layout accesses and retain consistent request shard identities.

• Revalidate opened shards under cob_lock and snapshot endpoints, target IDs, logical shard IDs, EC indices, and rebuild flags consistently.
• Make EC fetch, degraded reads, parity, and enumeration selection version-aware; propagate DER_STALE instead of using mismatched layouts.
• Reject stale target lists before fanout via normal task completion.
• Preserve saved EC indices for checksum and enumeration processing.
• Identify sub-anchors by logical shard ID and use fixed class widths for group-anchor arithmetic across extended layout changes.
• Skip success-output processing on failed attempts and validate key-to-anchor group boundaries against the requested map version.
• Use a stable stride for CPD classification and resolve leaders from classified entries; protect forced-leader lookup and timestamp updates.
• Reselect replicas after map changes, establish a new retry-cycle start, and preserve redundancy errors when no eligible replica remains.

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 'Object client may use inconsistent layout data during replica retry'
Status is 'Reopened'
Job should run at elevated priority (1)
https://daosio.atlassian.net/browse/DAOS-19636

[daosbuild3]

Test stage Functional Hardware Medium Provider 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-19248/2/execution/node/1987/log