RFR: 8315742: Open source several Swing Scroll related tests

[Tejesh R]

Open sourcing these Swing Scroll related tests:

javax/swing/JScrollBar/4495822/bug4495822.java
javax/swing/JScrollBar/4696826/bug4696826.java
javax/swing/JScrollBar/4842792/bug4842792.java
javax/swing/JScrollPane/4247092/bug4247092.java
javax/swing/JScrollPane/4264640/bug4264640.java
javax/swing/JScrollPane/4467063/bug4467063.java

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Commit messages:
 - Open source few ScrollPane and ScrollBar related Test

Changes: https://git.openjdk.org/jdk/pull/15839/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15839&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8315742
  Stats: 419 lines in 6 files changed: 419 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/15839.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15839/head:pull/15839

PR: https://git.openjdk.org/jdk/pull/15839