LUCENE-9703: Hunspell: prohibit FORBIDDENWORD words and their case variations

[donnerpeter]

Description

Dutch Ijs should not be accepted

Solution

Check for word forbiddenness earlier

Tests

Added Ijs case to IJ test

Checklist

Please review the following and check all that apply:

• I have reviewed the guidelines for How to Contribute and my code conforms to the standards described there to the best of my ability.
• I have created a Jira issue and added the issue ID to my pull request title.
• I have given Solr maintainers access to contribute to my PR branch. (optional but recommended)
• I have developed this patch against the master branch.
• I have run ./gradlew check.
• I have added tests for my changes.
• I have added documentation for the Ref Guide (for Solr changes only).