RFR: 8313424: JavaFX controls in the title bar [v68]

[Michael Strauß]

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

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

  add HeaderDragType

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

Changes:
  - all: https://git.openjdk.org/jfx/pull/1605/files
  - new: https://git.openjdk.org/jfx/pull/1605/files/7dc8f5f1..d1aa6b3b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1605&range=67
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1605&range=66-67

  Stats: 252 lines in 5 files changed: 226 ins; 6 del; 20 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