RFR: 8313424: JavaFX controls in the title bar [v63]

[Michael Strauß]

> Implementation of [`StageStyle.EXTENDED`](https://gist.github.com/mstr2/0befc541ee7297b6db2865cc5e4dbd09).

Michael Strauß has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 80 commits:

 - Merge branch 'master' into feature/extended-window
 - Remove StageStyle.EXTENDED_UTILITY
 - remove import
 - doc update
 - Merge branch 'master' into feature/extended-window
   
   # Conflicts:
   #	tests/manual/monkey/src/com/oracle/tools/fx/monkey/MainWindow.java
   #	tests/manual/monkey/src/com/oracle/tools/fx/monkey/tools/ModalWindow.java
 - documentation
 - documentation
 - tweak header button scaling at 100%
 - enable preview features in tests
 - add preview feature
 - ... and 70 more: https://git.openjdk.org/jfx/compare/8a61dd2b...3622b05b

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Changes: https://git.openjdk.org/jfx/pull/1605/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1605&range=62
  Stats: 6513 lines in 75 files changed: 5831 ins; 505 del; 177 mod
  Patch: https://git.openjdk.org/jfx/pull/1605.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1605/head:pull/1605

PR: https://git.openjdk.org/jfx/pull/1605