RFR: 8368972: Create implementation of menu bar accessibility component

[Alexander Zuev]

Create the accessibility peer for menu bar component also fix the problem when with the voiceover is on the <Ctrl>-F10 is pressed the name of the selected menu is not announced.

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Commit messages:
 - Fixing wrong copyright year
 - Fixing the assignment;
 - Fixed typo
 - 8368972: Create implementation of menu bar accessibility component

Changes: https://git.openjdk.org/jfx/pull/1927/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1927&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8368972
  Stats: 59 lines in 4 files changed: 54 ins; 2 del; 3 mod
  Patch: https://git.openjdk.org/jfx/pull/1927.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1927/head:pull/1927

PR: https://git.openjdk.org/jfx/pull/1927