RFR: 8358532: JFileChooser in GTK L&F still displays HTML filename

[Tejesh R]

[JDK-8139228](https://bugs.openjdk.org/browse/JDK-8139228) fix missed GTK updates for the same issue where file/directory name renders as `HTML text` instead of `plain text`.
Adding the same fix for GTK L&F.
Test for the fix : test/jdk/javax/swing/JFileChooser/HTMLFileName.java

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Commit messages:
 - GTK fix

Changes: https://git.openjdk.org/jdk/pull/25707/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25707&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8358532
  Stats: 6 lines in 1 file changed: 6 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/25707.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25707/head:pull/25707

PR: https://git.openjdk.org/jdk/pull/25707