RFR: 8328238: Convert few closed manual applet tests to main [v5]

[Prasanta Sadhukhan]

> Few closed manual applet tests are converted to main based and opensourced

Prasanta Sadhukhan has updated the pull request incrementally with one additional commit since the last revision:

  Remove getContentPane

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Changes:
  - all: https://git.openjdk.org/jdk/pull/18390/files
  - new: https://git.openjdk.org/jdk/pull/18390/files/bac1ecb3..89783161

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18390&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18390&range=03-04

  Stats: 8 lines in 1 file changed: 0 ins; 0 del; 8 mod
  Patch: https://git.openjdk.org/jdk/pull/18390.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18390/head:pull/18390

PR: https://git.openjdk.org/jdk/pull/18390