Remove Lucene split packages

[grcevski]

This PR proposes to fix the Lucene split package issue in LazySoftDeletesDirectoryReaderWrapper.

I did two things to make this work, one is a hack until we perhaps make a change in Lucene:

• (hack) I use SoftDeletesDirectoryReaderWrapper to make me a fresh CacheKey since we can't call the constructor.
• I copy pasted the applySoftDeletes code and removed the bits that were irrelevant (and causing us to bring more packages). Fortunately, the call to DocValuesFieldExistsQuery.getDocValuesDocIdSetIterator(field, reader) can't get us a reader back that has a non-null hasValue, so we could live without the iterator in DocValuesFieldUpdates (which is package private).

If we manage to get the DelegatingCacheHelper implementation as a public implementation in Lucene, then we get much better implementation.

closes #81981

[grcevski]

Hm, I realized there's an issue if reader.getReaderCacheHelper() is null. I can easily work around the null pointer here, but I need to somehow get a key inside the leaf and codec readers.

[ywelsch]

This feels like too much of a hack to bring into ES. It's effectively opening up the index multiple times now whenever a search hits a shard in the frozen tier (one extra time per lucene index, and then once per segment in the Lucene index) . Let's rather work towards exposing the right abstraction in Lucene.

[grcevski]

Yeah I agree, it's a total hack. I couldn't figure out a better way to get to a unique CacheKey. Let's try to get a change in Lucene.

[elasticmachine]

Pinging @elastic/es-core-infra (Team:Core/Infra)

[elasticsearchmachine]

Hi @grcevski, I've created a changelog YAML for you.

[grcevski]

@elasticmachine run Check labels

[ChrisHegarty]

LGTM

[elasticsearchmachine]

Hi @grcevski, I've updated the changelog YAML for you.