RFR: JDK-8312518 : [macos13] setFullScreenWindow() shows black screen on macOS 13 & above

[Harshitha Onkar]

A black screen is seen on newer versions of macOS (13.3 & above) when a window is set to full-screen using `setFullScreenWindow()`. The root cause was narrowed down to the shield level of the full-screen window vs the shield level of the captured display.

Following solutions were explored -

1. Setting `kCGMaximumWindowLevelKey` as the shield level for the full screen window. But setting the fullscreen window to maximum available window level might cause z-order issues when other popup/screen savers are involved.

          int shieldLevel = CGWindowLevelForKey(kCGMaximumWindowLevelKey);
          window.preFullScreenLevel = [nsWindow level];
          [nsWindow setLevel: shieldLevel];

2. Raise the windows level slightly (shieldLevel + 1) above the system shield window. 

            int shieldLevel = CGShieldingWindowLevel();
            window.preFullScreenLevel = [nsWindow level];
            [nsWindow setLevel: (shieldLevel + 1)]; 

3. Keeping the shielding level as-is and bringing the window to the foreground after display is captured. The 3rd approach **(also the one Apple recommends)** ensures that the full screen window has focus as well as being visible and also maintains the correct z-order. This solution works as expected on older (< 13.3) and newer versions (13.3 & above) of macOS.

          if (CGDisplayCapture(aID) == kCGErrorSuccess) {
                ...
                ...
                int shieldLevel = CGShieldingWindowLevel();
                window.preFullScreenLevel = [nsWindow level];
                [nsWindow setLevel: shieldLevel];
                [nsWindow makeKeyAndOrderFront: nil];
            }

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Commit messages:
 - removed extra line
 - test changes
 - summary updated
 - test changes
 - initial changes

Changes: https://git.openjdk.org/jdk/pull/17358/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17358&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8312518
  Stats: 91 lines in 2 files changed: 90 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/17358.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17358/head:pull/17358

PR: https://git.openjdk.org/jdk/pull/17358