[Bug fix] Fix default exporter settings

[ansjcy]

Description

The default settings for exporters were changed in #217, but when we start OpenSearch with query insights and run queries, there's no data exported to local index.

This PR fixes the issue by deeply refactoring the related logic.

Issues Resolved

Closes #232

Testing

• Run OpenSearch with query-insights, create document and do searches
• Wait for 5 minutes (default window)
• Check local indices

curl -X GET "localhost:9200/_cat/indices"
yellow open my-index-0                   ih6DMkwqQsKurHlwu5kDZA 1 1 1 0    5kb    5kb
yellow open top_queries-2025.01.31-62142 VPP6qMsQQgm3-oUj1PHUdA 1 1 2 4 48.6kb 48.6kb

• Disable local index exporter

curl -X PUT 'localhost:9200/_cluster/settings' -H 'Content-Type: application/json' -d'
{
    "persistent" : {
        "search.insights.top_queries.exporter.type" : "none"
    }
}'

• Check local indices

curl -X GET "localhost:9200/_cat/indices"
yellow open my-index-0 ih6DMkwqQsKurHlwu5kDZA 1 1 1 0 5kb 5kb

• Reenable it

curl -X PUT 'localhost:9200/_cluster/settings' -H 'Content-Type: application/json' -d'
{
    "persistent" : {
        "search.insights.top_queries.exporter.type" : "local_index"
    }
}'

• do search, wait for 5 minutes
• check local indices

curl -X GET "localhost:9200/_cat/indices"
yellow open my-index-0                   ih6DMkwqQsKurHlwu5kDZA 1 1 1 0    5kb    5kb
yellow open top_queries-2025.01.31-62142 xyZmoWOvTreNVlVaosBWJA 1 1 1 2 24.3kb 24.3kb

• set local index to debug and check local index

curl -X GET "localhost:9200/_cat/indices"
yellow open my-index-0 ih6DMkwqQsKurHlwu5kDZA 1 1 1 0 5kb 5kb

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