RFR: 8249737: java.lang.RuntimeException: Too many touch points reported

[Jose Pereda]

Using a digitizer tablet with a pen that works with Windows or MacOS, it works fine on MacOS, but throws a RTE on Windows 10. On MacOS there are only MouseEvents, while on Windows there are both MouseEvents and TouchEvents mixed together. 

Windows only uses [direct](https://github.com/openjdk/jfx/blob/master/modules/javafx.graphics/src/main/native-glass/win/ViewContainer.cpp#L1271) touch events natively, and that works for touch screens. 

But when touch pads are used generate mainly indirect touch events.  

There is already a way to find the source of the touch event (touch screen or touch pad/pen), via [isTouchEvent()](https://github.com/openjdk/jfx/blob/master/modules/javafx.graphics/src/main/native-glass/win/ViewContainer.cpp#L62), so this PR uses that method to set `isDirect` based on the source: true or direct for touch screen and false or indirect for touch pad/pen. 

Tested successfully using a touch screen and a touch pad with pen.

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Commit messages:
 - Set isDirect using isTouchEvent() that returns the source of the touch event (screen or pen)

Changes: https://git.openjdk.java.net/jfx/pull/394/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=394&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8249737
  Stats: 4 lines in 1 file changed: 0 ins; 1 del; 3 mod
  Patch: https://git.openjdk.java.net/jfx/pull/394.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/394/head:pull/394

PR: https://git.openjdk.java.net/jfx/pull/394