RFR: 8371080: RichTextArea: missing styles in Caspian

Mon Nov 3 19:57:45 UTC 2025

Added missing RichTextArea styles to `caspian.css`.

This is a trivial change.

To test, one can use the latest Monkey Tester Window -> Stylesheet menu.
https://github.com/andy-goryachev-oracle/MonkeyTest

<img width="1021" height="350" alt="Screenshot 2025-11-03 at 11 50 50" src="https://github.com/user-attachments/assets/8559e702-5294-4a98-a251-f3b2283d7a83" />

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Commit messages:
 - added rich text area styles to caspian.css

Changes: https://git.openjdk.org/jfx/pull/1959/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1959&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8371080
  Stats: 80 lines in 1 file changed: 79 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jfx/pull/1959.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1959/head:pull/1959

PR: https://git.openjdk.org/jfx/pull/1959