LUCENE-9771: Hunspell: don't lookup word roots unnecessarily to check…

[donnerpeter]

… flags

Description

Hunspell performs unnecessary root lookups from the times before Root class was introduced

Solution

Cleanup and shorten code by using Root.entryId instead of guessing flags by lookupWord

Tests

None, just a cleanup.

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).