RFR: 8202296: Monocle MouseInput doesn't send keyboard modifiers in events.

[Tom Schindl]

Extract keystate and add to the existing modifier mask, to support eg
multi-select

https://bugs.openjdk.java.net/browse/JDK-8202296

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Commit messages:
 - 8202296: Monocle MouseInput doesn't send keyboard modifiers in events.

Changes: https://git.openjdk.java.net/jfx/pull/170/files
 Webrev: https://webrevs.openjdk.java.net/jfx/170/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8202296
  Stats: 20 lines in 1 file changed: 14 ins; 0 del; 6 mod
  Patch: https://git.openjdk.java.net/jfx/pull/170.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/170/head:pull/170

PR: https://git.openjdk.java.net/jfx/pull/170