RFR: 8366986: [Win] Incorrect position and size after hiding iconified stage [v2]

[Martin Fox]

> When a top-level HWND is iconified its window rect is updated to a hard-coded location (something like -32000, -32000) and a smaller width and height. For this reason we should not send notifyMove or notifyResize events for an iconified stage.  This PR adds a check while handling WM_SHOWWINDOW to catch the case where a stage is hidden while iconified. This matches similar existing checks like the one for WM_MOVE.

Martin Fox has updated the pull request incrementally with one additional commit since the last revision:

  Disabled system test on Linux, DECORATED stage is changing height

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Changes:
  - all: https://git.openjdk.org/jfx/pull/1889/files
  - new: https://git.openjdk.org/jfx/pull/1889/files/3fbfcef0..77135f53

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1889&range=01
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1889&range=00-01

  Stats: 4 lines in 1 file changed: 4 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jfx/pull/1889.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1889/head:pull/1889

PR: https://git.openjdk.org/jfx/pull/1889