DAOS-19288 control: Add allow-numa-imbalance flag to config generate

[tanabarr]

Add --allow-numa-imbalance/-n flag to dmg and daos_server config
generate commands. This flag distributes NVMe devices equally across
engines regardless of NUMA affinity.

Without this flag, config generation respects NUMA affinity and balances
device assignment by giving entrance the lowest common denominator
SSD count across NUMA nodes within the cluster.

With this flag enabled:
- All available SSDs are collected from all NUMA nodes
- SSDs are distributed equally across all engines
- Distribution ignores NUMA node boundaries
- If total SSDs not evenly divisible, uses maximum divisible number
- Remainder SSDs are not included in generated config
- Notice logged when SSDs unused due to remainder
- Generated config incl. allow_numa_imbalance: true to allow boot

This maximizes device utilization in heterogeneous environments but may
result in suboptimal performance due to cross-NUMA memory access.

Features: control
Signed-off-by: Tom Nabarro tom.nabarro@intel.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).

[daosbuild3]

Test stage Unit Test completed with status UNSTABLE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net/job/daos-stack/job/daos//view/change-requests/job/PR-18621/1/testReport/

[github-actions]

Ticket title is 'Add config generate flag to ignore NVMe NUMA affinity'
Status is 'In Progress'
https://daosio.atlassian.net/browse/DAOS-19288

[daosbuild3]

Test stage Unit Test completed with status UNSTABLE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net/job/daos-stack/job/daos//view/change-requests/job/PR-18621/2/testReport/

[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-18621/3/execution/node/547/log

[daosbuild3]

Test stage Build on EL 8 completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-18621/3/execution/node/595/log

[daosbuild3]

Test stage Build on Leap 15 completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-18621/3/execution/node/641/log