RFR: Merge jfx19 [v2]

[Kevin Rushforth]

> Merge `jfx19` into `master`.

Kevin Rushforth has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 16 commits:

 - Merge jfx19
 - 8289605: Robot capture tests fail intermittently on Mac M1
   
   Reviewed-by: kcr
 - 8289397: Fix warnings: Possible accidental assignment in place of a comparison. A condition expression should not be reduced to an assignment
   
   Reviewed-by: kcr
 - 8290530: Bump minimum JDK version for JavaFX to JDK 17
   
   Reviewed-by: prr, jvos
 - 8290990: Clear .root style class from a root node that is removed from a Scene/SubScene
   
   Reviewed-by: jhendrikx, aghaisas, mhanl
 - 8285881: Update WebKit to 614.1
   
   Co-authored-by: Ambarish Rapte <arapte at openjdk.org>
   Co-authored-by: Kevin Rushforth <kcr at openjdk.org>
   Co-authored-by: Jay Bhaskar <jbhaskar at openjdk.org>
   Reviewed-by: kcr, arapte, mstrauss, jvos
 - 8290527: Bump macOS GitHub actions to macOS 11
   
   Reviewed-by: arapte
 - 8289388: Fix warnings: method is overriding a synchronized method without being synchronized
   
   Reviewed-by: kcr
 - 8289389: Fix warnings: type should also implement hashCode() since it overrides Object.equals()
   
   Reviewed-by: kcr
 - Merge
 - ... and 6 more: https://git.openjdk.org/jfx/compare/5febacae...1679f5cc

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

Changes: https://git.openjdk.org/jfx/pull/860/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=860&range=01
  Stats: 454251 lines in 7392 files changed: 301187 ins; 110186 del; 42878 mod
  Patch: https://git.openjdk.org/jfx/pull/860.diff
  Fetch: git fetch https://git.openjdk.org/jfx pull/860/head:pull/860

PR: https://git.openjdk.org/jfx/pull/860