[jdk21u-dev] RFR: 8354106: Clean up and open source KeyEvent related tests (Part 2)

[Satyen Subramaniam]

Backporting JDK-8354106: Clean up and open source KeyEvent related tests (Part 2). Adds two 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 e163a76f2bacf06980026feb7e645e616ffe2ad4

Changes: https://git.openjdk.org/jdk21u-dev/pull/2128/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=2128&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8354106
  Stats: 212 lines in 2 files changed: 212 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/2128.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/2128/head:pull/2128

PR: https://git.openjdk.org/jdk21u-dev/pull/2128