[jdk21u-dev] RFR: 8354472: Clean up and open source KeyEvent related tests (Part 3)

[Satyen Subramaniam]

Backporting JDK-8354472: Clean up and open source KeyEvent related tests (Part 3). Adds five key event tests. Ran GHA Sanity Checks, local Tier 1 and 2, and new tests directly. Patch is clean. Backporting for parity with Oracle.

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Commit messages:
 - Backport cd2d49f7119459f07844ce8201ca2320850cd51f

Changes: https://git.openjdk.org/jdk21u-dev/pull/2141/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=2141&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8354472
  Stats: 531 lines in 5 files changed: 531 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/2141.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/2141/head:pull/2141

PR: https://git.openjdk.org/jdk21u-dev/pull/2141