Expose Japanese completion filter to kuromoji analysis plugin

[mocobeta]

This adds analysis factories of JapaneseCompletionFilter and JapaneseCompletionAnalyzer (https://issues.apache.org/jira/browse/LUCENE-10102) to kuromoji plugin.

This is expected to be used in combination with Completion Suggester. For example:

# working example (we are running this setting on 7.x)
"mappings": {
    "properties": {
      "suggest_ja": {
        "type": "completion",
        "analyzer": "kuromoji_completion_index",
        "search_analyzer": "kuromoji_completion_query",
        "preserve_separators": false,
        "preserve_position_increments": true,
        "max_input_length": 50
      },
      "suggest_en": {
        "type": "completion",
        "analyzer": "standard",
        "preserve_separators": false,
        "preserve_position_increments": true,
        "max_input_length": 50
      }
    }
  }

Or, for searching use-cases, this could be used as a replacement of kuromoji_readingform; though we have not used it for searching.

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[mocobeta]

I'd be happy if I could get your feedback.

[elasticmachine]

Pinging @elastic/es-search (Team:Search)

[romseygeek]

@elasticmachine ok to test

[romseygeek]

Thanks @mocobeta, this looks great! Assuming that CI is happy I am good to merge this.

[romseygeek]

@elasticmachine update branch

[mocobeta]

Thanks for merging!