RFR: 8316164: Opensource JMenuBar manual test

[Prasanta Sadhukhan]

JMenubar manual applet test converted to automated and opensourced

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Commit messages:
 - 8316164: Opensource JMenuBar manual test

Changes: https://git.openjdk.org/jdk/pull/15717/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15717&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8316164
  Stats: 128 lines in 1 file changed: 128 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/15717.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15717/head:pull/15717

PR: https://git.openjdk.org/jdk/pull/15717