[jdk21u-dev] RFR: 8353320: Open source more Swing text tests

[Goetz Lindenmaier]

I backport this test change as it also goes to 21.0.9-oracle

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Commit messages:
 - Backport 74c2d8f41bbb770e959a77ae1ce468162d68beaf

Changes: https://git.openjdk.org/jdk21u-dev/pull/1796/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=1796&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8353320
  Stats: 418 lines in 9 files changed: 418 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/1796.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/1796/head:pull/1796

PR: https://git.openjdk.org/jdk21u-dev/pull/1796