RFR: JDK-8328299 : Convert DnDFileGroupDescriptor.html applet test to main

[Harshitha Onkar]

Following test java/awt/dnd/DnDFileGroupDescriptor/DnDFileGroupDescriptor.html is converted to main using PassFailJFrame.

This test is currently problem-listed on macOS and linux, but as per the previous JBS bugs [[JDK-6242241](https://bugs.openjdk.org/browse/JDK-6242241), [JDK-8080185](https://bugs.openjdk.org/browse/JDK-8080185), [JDK-7147083](https://bugs.openjdk.org/browse/JDK-7147083)] this test was original created for testing DnD of MS Outlook attachments on Windows system.

Based on the test history and JBS details, I believe this should be windows-only test and should NOT be problemlisted on macOS and linux as it is **not applicable**.

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Commit messages:
 - typo
 - windows check added
 - EOF newline added
 - problemlist.txt changes

Changes: https://git.openjdk.org/jdk/pull/18335/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18335&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8328299
  Stats: 266 lines in 3 files changed: 44 ins; 187 del; 35 mod
  Patch: https://git.openjdk.org/jdk/pull/18335.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18335/head:pull/18335

PR: https://git.openjdk.org/jdk/pull/18335