ICU-22304 Miscellanous PersonNameFormatter fixes; made ExhaustivePers…

[richgillam]

…onNameFormatterTest into a real unit test.

Checklist

• Required: Issue filed: https://unicode-org.atlassian.net/browse/ICU-22304
• Required: The PR title must be prefixed with a JIRA Issue number.
• Required: The PR description must include the link to the Jira Issue, for example by completing the URL in the first checklist item
• Required: Each commit message must be prefixed with a JIRA Issue number.
• Issue accepted (done by Technical Committee after discussion)
• Tests included, if applicable
• API docs and/or User Guide docs changed or added, if applicable

[pedberg-icu]

Cool test features I did not know about!

[FrankYFTang]

I belive the landing of this PR break the test
See the post merge report on https://github.com/unicode-org/icu/runs/15214572341
from https://github.com/unicode-org/icu/commits/main

The failure is

"
[junit] Running com.ibm.icu.dev.test.format.ExhaustivePersonNameFormatterTest
[junit] Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.012 sec
"

[richgillam]

@pedberg-icu has a couple pull requests pending that should fix this...