RFR: 8340326: Remove references to Applet in core-libs/security tests

[Justin Lu]

Please review this PR which removes usages of Applet within the corelibs tests. This includes both code usage as well as occurrences of the word.

There were more files found than the ones included in this PR, please see the comment on the JBS issue for the reason why they were not included. In general, I removed the file if the entirety was focused on Applet, otherwise I removed the portions applicable.

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Commit messages:
 - init

Changes: https://git.openjdk.org/jdk/pull/21096/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21096&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8340326
  Stats: 433 lines in 11 files changed: 2 ins; 411 del; 20 mod
  Patch: https://git.openjdk.org/jdk/pull/21096.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21096/head:pull/21096

PR: https://git.openjdk.org/jdk/pull/21096