RFR: 8315609: Open source few more swing text/html tests

[Prasanta Sadhukhan]

Few closed swing text/html tests are open sourced

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Commit messages:
 - 8315609: Open source few more swing text/html tests

Changes: https://git.openjdk.org/jdk/pull/15607/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15607&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8315609
  Stats: 422 lines in 4 files changed: 422 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/15607.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15607/head:pull/15607

PR: https://git.openjdk.org/jdk/pull/15607