Add the `-fx-platform` media query (similar to `-moz-platform` in Firefox) that allows applications to switch styles based on the operating system on which the application is running.
--------- - [x] I confirm that I make this contribution in accordance with the [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). ------------- Commit messages: - Platform media query Changes: https://git.openjdk.org/jfx/pull/2193/files Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=2193&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8374822 Stats: 146 lines in 6 files changed: 131 ins; 0 del; 15 mod Patch: https://git.openjdk.org/jfx/pull/2193.diff Fetch: git fetch https://git.openjdk.org/jfx.git pull/2193/head:pull/2193 PR: https://git.openjdk.org/jfx/pull/2193
