RFR: 8353832: Opensource FontClass, Selection and Icon tests

[Abhishek Kumar]

Font Class, Selection adn Icon related Applet tests are converted to manual and open sourced.

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Commit messages:
 - Remove unused variable, comment change
 - Applet test converted and open-sourced

Changes: https://git.openjdk.org/jdk/pull/24615/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24615&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8353832
  Stats: 350 lines in 4 files changed: 350 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/24615.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24615/head:pull/24615

PR: https://git.openjdk.org/jdk/pull/24615