RFR: 8368478: RichTextArea: add IME support

[Lukasz Kostyra]

On Thu, 16 Oct 2025 19:59:06 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

> Adds Input Method Editor (IME) support to `RichTextArea`/`CodeArea`.
> 
> Tested on macOS and Windows 11 with Japanese and Chinese (pinyin) input methods.
> Please test this on Linux, even though there is no platform-specific code in this PR (should work the same way it does in `TextArea`/`TextField`)
> 
> For testing, one can use the updated Monkey Tester
> https://github.com/andy-goryachev-oracle/MonkeyTest
> (optionally enable IME events in stdout with Logging -> IME Monitor)

Looks good. I tested this on Windows with rich editor demo and using both polish and spanish IME shortcuts - all work fine after this change

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Marked as reviewed by lkostyra (Reviewer).

PR Review: https://git.openjdk.org/jfx/pull/1938#pullrequestreview-3376799883