[jdk21u-dev] RFR: 8353655: Clean up and open source KeyEvent related tests (Part 1)

[Bara' Hasheesh]

Backport JDK-8353655 for parity with oracle.

Clean backport, adding new tests.

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Commit messages:
 - Backport ad7c475fb1e23f583a33d58f0bd73ea0fb56740c

Changes: https://git.openjdk.org/jdk21u-dev/pull/1862/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=1862&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8353655
  Stats: 316 lines in 3 files changed: 316 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/1862.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/1862/head:pull/1862

PR: https://git.openjdk.org/jdk21u-dev/pull/1862