RFR: 8311895: CSS Transitions [v15]

[Michael Strauß]

> Implementation of [CSS Transitions](https://gist.github.com/mstr2/c72f8c9faa87de14926978f517a6018a).
> 
> ### Example
> 
> .button {
>     -fx-background-color: dodgerblue;
> }
> 
> .button:hover {
>     -fx-background-color: red;
>     -fx-scale-x: 1.1;
>     -fx-scale-y: 1.1;
> 
>     transition: -fx-background-color 0.5s ease,
>                 -fx-scale-x 0.5s ease,
>                 -fx-scale-y 0.5s ease;
> }
> 
> <img src="https://user-images.githubusercontent.com/43553916/184781143-0520fbfe-54bf-4b8d-93ac-834708e46500.gif" width="200"/>
> 
> ### Limitations
> This implementation supports both shorthand and longhand notations for the `transition` property. However, due to limitations of JavaFX CSS, mixing both notations doesn't work:
> 
> .button {
>     transition: -fx-background-color 1s;
>     transition-easing-function: linear;
> }
> 
> This issue should be addressed in a follow-up enhancement.

Michael Strauß has updated the pull request incrementally with two additional commits since the last revision:

 - update 'since' tags
 - Fix javadoc error

-------------

Changes:
  - all: https://git.openjdk.org/jfx/pull/870/files
  - new: https://git.openjdk.org/jfx/pull/870/files/f7ab6db3..137a00c7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=870&range=14
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=870&range=13-14

  Stats: 14 lines in 3 files changed: 8 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jfx/pull/870.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/870/head:pull/870

PR: https://git.openjdk.org/jfx/pull/870