[jfx17u] RFR: 8298728: Cells in VirtualFlow jump after resizing

[Jose Pereda]

Almost clean backport of 8298728: Cells in VirtualFlow jump after resizing
Reviewed-by: aghaisas, angorya

There was a small conflict in VirtualFlowTest::CellStub, due to JDK-8297414:

-        setSkin(new SkinStub<CellStub>(this));
+        setSkin(new SkinStub<>(this));

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Commit messages:
 - 8298728: Cells in VirtualFlow jump after resizing

Changes: https://git.openjdk.org/jfx17u/pull/149/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx17u&pr=149&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8298728
  Stats: 130 lines in 4 files changed: 111 ins; 2 del; 17 mod
  Patch: https://git.openjdk.org/jfx17u/pull/149.diff
  Fetch: git fetch https://git.openjdk.org/jfx17u.git pull/149/head:pull/149

PR: https://git.openjdk.org/jfx17u/pull/149