[jdk21u-dev] RFR: 8340555: Open source DnD tests - Set4

[Goetz Lindenmaier]

I backport this for parity with 21.0.8-oracle

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Commit messages:
 - Backport 0dd49970428e08d35996752ba0878a97fb6f8530

Changes: https://git.openjdk.org/jdk21u-dev/pull/1572/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=1572&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8340555
  Stats: 837 lines in 7 files changed: 837 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/1572.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/1572/head:pull/1572

PR: https://git.openjdk.org/jdk21u-dev/pull/1572