RFR: 8313424: JavaFX controls in the title bar [v36]

[Michael Strauß]

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

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

  fix resizable states for GTK windows

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

Changes:
  - all: https://git.openjdk.org/jfx/pull/1605/files
  - new: https://git.openjdk.org/jfx/pull/1605/files/8d5d7b87..eaafd9f0

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1605&range=35
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1605&range=34-35

  Stats: 62 lines in 4 files changed: 23 ins; 20 del; 19 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