RFR: 8354478: Improve StageStyle documentation

Sun Apr 13 15:29:15 UTC 2025

Improve StageStyle Documentation

- Update `StageStyle.UTILITY`:
Clarified that UTILITY stages may impose platform-specific restrictions on window states, such as preventing maximize, minimize (iconify), and fullscreen operations.

- Update `StageStyle.UNDECORATED`:
Improved the description to clarify that although UNDECORATED removes standard window decorations (title bar, borders, and controls), window operations like minimize, maximize, and fullscreen may still be allowed programmatically or via platform-specific functions such as key shortcuts or menu options.

- Remove mention of solid white background:
This seems to be not true anymore, even withou a `Scene` (or there's a bug)

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

Commit messages:
 - 8354478: Improve StageStyle documentation

Changes: https://git.openjdk.org/jfx/pull/1776/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1776&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8354478
  Stats: 11 lines in 1 file changed: 7 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jfx/pull/1776.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1776/head:pull/1776

PR: https://git.openjdk.org/jfx/pull/1776