RFR: 8340985: Open source some Desktop related tests

[Alexander Zuev]

Clean up and open source five regression tests related to java.awt.Desktop component.

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Commit messages:
 - 8340985: Open source some Desktop related tests

Changes: https://git.openjdk.org/jdk/pull/21321/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21321&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8340985
  Stats: 580 lines in 5 files changed: 580 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/21321.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21321/head:pull/21321

PR: https://git.openjdk.org/jdk/pull/21321