RFR: 8340432: Open source some MenuBar tests - Set2

[Damon Nguyen]

Following tests are added as part of this PR:

/java/awt/MenuBar/MenuBarOnDisabledFrame/MenuBarOnDisabledFrame.java (Manual with PassFailJFrame)
/java/awt/MenuBar/MenuBarAddRemoveTest/MenuBarAddRemoveTest.java (Manual with PassFailJFrame)
/java/awt/MenuBar/SetHelpMenuTest/SetHelpMenuTest.java (Manual with PassFailJFrame)
/java/awt/MenuBar/MenuBarVisuals/MenuBarVisuals.java (Manual with PassFailJFrame)

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Commit messages:
 - Remove escape chars
 - Initial commit to open

Changes: https://git.openjdk.org/jdk/pull/21251/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21251&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8340432
  Stats: 326 lines in 4 files changed: 326 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/21251.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21251/head:pull/21251

PR: https://git.openjdk.org/jdk/pull/21251