RFR: 8252863: Spinner keeps spinning if removed from Scene [v3]

[Ajit Ghaisas]

On Mon, 19 Dec 2022 07:20:11 GMT, Karthik P K <kpk at openjdk.org> wrote:

>> Spinner was not stopping because it was getting removed from scene before the mouse release event handler was getting invoked.
>> 
>> Added listener for `sceneProperty` so that when Spinner is removed from the scene, `stopSpinning` method shall be called.
>> 
>> Added unit test to validate the fix
>
> Karthik P K has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Address review comments

Fix looks good to me!

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Marked as reviewed by aghaisas (Reviewer).

PR: https://git.openjdk.org/jfx/pull/976