RFR: 8339943: Frame not disposed in java/awt/dnd/DropActionChangeTest.java

[Manukumar V S]

Stabilized the test by disposing the frame at the end, adding an auto delay,  called panel.getLocationOnScreen() in invokeAndWait(), formatting changes, etc
And for better debugging, added captureScreen() for failure cases.

Testing:
Tested using mach5 in all available platforms and attached the link in bug as a comment.

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Commit messages:
 - 8339943: Frame not disposed in java/awt/dnd/DropActionChangeTest.java

Changes: https://git.openjdk.org/jdk/pull/20951/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20951&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8339943
  Stats: 60 lines in 1 file changed: 33 ins; 13 del; 14 mod
  Patch: https://git.openjdk.org/jdk/pull/20951.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20951/head:pull/20951

PR: https://git.openjdk.org/jdk/pull/20951