RFR: 8348095: [Linux] Menu shows up in wrong position when using i3 windows manager in full screen mode

[Thiago Milczarek Sayao]

The issue was with the view's position, specifically the content's X and Y coordinates relative to the window, including its decorations. When in fullscreen mode, the window remains decorated, but the decorations are hidden. As a result, the content's position needs to be recalculated to account for the window's adjusted layout.

It's not specific to i3.

I used `gdk_window_get_root_origin`   because GTK will try harder to find the value, even if `_NET_FRAME_EXTENTS` is not supported on some Window Manager.

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Commit messages:
 - Forgot debug print
 - 8348095: [Linux] Menu shows up in wrong position when using i3 windows manager in full screen mode

Changes: https://git.openjdk.org/jfx/pull/1702/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1702&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8348095
  Stats: 19 lines in 3 files changed: 3 ins; 1 del; 15 mod
  Patch: https://git.openjdk.org/jfx/pull/1702.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1702/head:pull/1702

PR: https://git.openjdk.org/jfx/pull/1702