RFR: 8306871: Open source more AWT Drag & Drop tests [v2]

[Damon Nguyen]

> This PR open sources more AWT DnD & Event related tests

Damon Nguyen has updated the pull request incrementally with one additional commit since the last revision:

  Fix syntax. Edit comment

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Changes:
  - all: https://git.openjdk.org/jdk/pull/13725/files
  - new: https://git.openjdk.org/jdk/pull/13725/files/9999d9cc..97383c7f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13725&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13725&range=00-01

  Stats: 6 lines in 3 files changed: 0 ins; 1 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/13725.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13725/head:pull/13725

PR: https://git.openjdk.org/jdk/pull/13725