Merge branch '3487487-improve-ai-search' into '1.0.x'

modules/ai_search/ai_search.services.yml

modules/ai_search/src/AiVdbProviderSearchApiInterface.php

modules/ai_search/src/Base/EmbeddingStrategyPluginBase.php

modules/ai_search/src/EmbeddingStrategyInterface.php

modules/ai_search/src/EmbeddingStrategyPluginManager.php

...Plugin/EmbeddingStrategy/AveragePoolEmbeddingStrategy.php

.../ai_search/src/Plugin/EmbeddingStrategy/EmbeddingBase.php

...les/ai_search/src/Plugin/QueueWorker/ChunkQueueWorker.php

...rc/Plugin/search_api/backend/SearchApiAiSearchBackend.php

src/Base/AiVdbProviderClientBase.php