[jfx21u] RFR: 8319779: SystemMenu: memory leak due to listener never being removed

[Johan Vos]

Backport of  8323787: Mac System MenuBar throws IOB exception

Required manual changes as the location of the test has changed.

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Commit messages:
 - 8319779: SystemMenu: memory leak due to listener never being removed

Changes: https://git.openjdk.org/jfx21u/pull/63/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx21u&pr=63&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8319779
  Stats: 603 lines in 5 files changed: 462 ins; 132 del; 9 mod
  Patch: https://git.openjdk.org/jfx21u/pull/63.diff
  Fetch: git fetch https://git.openjdk.org/jfx21u.git pull/63/head:pull/63

PR: https://git.openjdk.org/jfx21u/pull/63