RFR: 8315726: Open source several AWT applet tests

[Alexander Zvegintsev]

Some closed AWT test are open sourced.

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Commit messages:
 - initial

Changes: https://git.openjdk.org/jdk/pull/15671/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15671&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8315726
  Stats: 867 lines in 5 files changed: 867 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/15671.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15671/head:pull/15671

PR: https://git.openjdk.org/jdk/pull/15671