RFR: 8345348: CSS Media Queries

[Michael Strauß]

Implementation of [CSS media queries](https://gist.github.com/mstr2/cbb93bff03e073ec0c32aac317b22de7).

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

Commit messages:
 - Add persistentScrollBars media feature
 - Merge branch 'master' into feature/media-queries
 - Merge branch 'master' into feature/media-queries
 - Implementation of media queries

Changes: https://git.openjdk.org/jfx/pull/1655/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1655&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8345348
  Stats: 4607 lines in 37 files changed: 3510 ins; 1026 del; 71 mod
  Patch: https://git.openjdk.org/jfx/pull/1655.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1655/head:pull/1655

PR: https://git.openjdk.org/jfx/pull/1655