RFR: 8328577: Toolbar's overflow button overlaps the items [v3]

[eduardsdv]

> This change fixes the calculation of which nodes go to the toolbar and which go to the overflow menu.
> It is now determined before the nodes are removed from the scene graph.
> This is important because the values returned by ``Node.prefWidth(..)``/``Node.prefHeight(..)`` may depend on whether the node is added to the scene graph.
> 
> Furthermore I corrected the ``hasOveflow`` value passed to the ``organizeOverflow(double, boolean)`` in ``correctOverflow(double)``.

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

  JDK-8328577: Add unit test

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Changes:
  - all: https://git.openjdk.org/jfx/pull/1434/files
  - new: https://git.openjdk.org/jfx/pull/1434/files/82994291..09dcc48d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1434&range=02
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1434&range=01-02

  Stats: 69 lines in 1 file changed: 67 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jfx/pull/1434.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1434/head:pull/1434

PR: https://git.openjdk.org/jfx/pull/1434