RFR: 8234189: [TEST_BUG] Remove ignored and invalid graphics unit tests

[Ambarish Rapte]

Following unit tests are to be removed:
1. test.com.sun.javafx.iio.ImageLoaderScalingTest.testAllTheScalesJPG:
Color of a pixel in original and scaled jpg image can not be guarantted to be same.

2. test.javafx.scene.layout.BackgroundSizeTest.negativeWidthThrowsException3
test.javafx.scene.layout.BackgroundSizeTest.negativeHeightThrowsException3:
Double.MIN_VALUE is not < 0 and there are tests included for negative value.

3.test.javafx.scene.input.PasteboardTest:  Pasteboard is removed.

4. test.javafx.scene.input.TouchEventTest.shouldThrowREOnLostIndirectRelease:
Indirect gesture touch events are not supported yet. There will be lot of more tests needed once we decide to support the Indirect gesture events. This test can be reintroduced after that.

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Commits:
 - a8ecc824: Remove ignored and invalid graphics unit tests

Changes: https://git.openjdk.java.net/jfx/pull/38/files
 Webrev: https://webrevs.openjdk.java.net/jfx/38/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8234189
  Stats: 167 lines in 4 files changed: 0 ins; 164 del; 3 mod
  Patch: https://git.openjdk.java.net/jfx/pull/38.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/38/head:pull/38

PR: https://git.openjdk.java.net/jfx/pull/38