RFR: 8307325: Verify the focus owner when non focused windows requesting focus

[Ravi Gupta]

Write a test Check, when the top level Window is not the focused Window requesting for focus and becoming the Focus Owner for any Component in that Window checking the following

1.The Component is the Focus Owner and the Window becomes the focused Window If the platform supports cross requesting focus
across Windows.
2.The request is remembered and  be granted when the Window is later focused If the platform does not support requesting focus
across Windows.

Testing:
Tested using Mach5(20 times per platform) in macos,linux and windows and got all pass.

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Commit messages:
 - 8307325: Verify the focus owner when non focused windows requesting focus

Changes: https://git.openjdk.org/jdk/pull/13790/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13790&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8307325
  Stats: 149 lines in 1 file changed: 149 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/13790.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13790/head:pull/13790

PR: https://git.openjdk.org/jdk/pull/13790