RFR: 8328238: Convert few closed manual applet tests to main [v6]

[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 from other tests

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/18390/files
  - new: https://git.openjdk.org/jdk/pull/18390/files/89783161..06d7407c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18390&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18390&range=04-05

  Stats: 3 lines in 2 files changed: 0 ins; 0 del; 3 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