RFR: 8354928: Clean up and open source some miscellaneous AWT tests

[Alexander Zuev]

Clean up and open source some tests related to event processing in AWT library.

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Commit messages:
 - 8354928: Clean up and open source some miscellaneous AWT tests

Changes: https://git.openjdk.org/jdk/pull/24755/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24755&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8354928
  Stats: 499 lines in 4 files changed: 499 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/24755.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24755/head:pull/24755

PR: https://git.openjdk.org/jdk/pull/24755