DAOS-19646 cart: self_test option to dump group

[frostedcmos]

• Added '-d' option to self_test to dump group rank:uri mapping along with self address.

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 'Add self_test option to dump group info'
Status is 'Open'
https://daosio.atlassian.net/browse/DAOS-19646

[frostedcmos]

Example output:
`

Dumping info:
self_uri: ofi+tcp://10.214.209.145:33303
group: 'g1'
group size: 1
daos_agent: no
attach_patch: /tmp/g1.attach_info
ranks:
        0 : ofi+tcp://10.214.209.145:31416