DAOS-18592 control: Only use joined ranks when calculating pool size

[tanabarr]

In order to avoid failing pool create with storage percentage (-z X%)
when ranks have been stopped, only take into account joined ranks when
calculating maximum available pool sizes.

Features: pool

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 'Pool create with percentage fails after stopping rank 0'
Status is 'In Progress'
https://daosio.atlassian.net/browse/DAOS-18592

[daosbuild3]

Test stage Functional Hardware Large 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-17580/1/execution/node/1274/log

[knard38]

The uni test TestControl_getMaxPoolSize() should probably be update with these new use cases.

[knard38]

The newFilterRankFunc() should probably be updated to not support empty RankList as all ranks.
From my understanding, if the new filtering on joined ranks produce an empty list it will be interpreted as all ranks by newFilterRankFunc().