RFR: 8377745: VoiceOver Identifies Hyperlink as Text

[Jeremy Wood]

If we use `new AccessibleRole("AXLink") {}`, then VoiceOver reads this more like other native apps.

There isn't a similar precedent in CAccessibility for creating custom AccessibleRoles, so I won't mind if this PR is declined. (But I don't know off the top of my head where else to inject code to get the desired result...)

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Commit messages:
 - 8377745: add unit test
 - 8377745: use custom "AXLink" AccessibleRole

Changes: https://git.openjdk.org/jdk/pull/29686/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29686&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8377745
  Stats: 134 lines in 2 files changed: 129 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/29686.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29686/head:pull/29686

PR: https://git.openjdk.org/jdk/pull/29686