IBX-9846: Added search using embeddings

[mikadamczyk]

🎫 Issue	IBX-9846

Description:

Introduces foundational embedding support at the Ibexa Core level:

• New query abstractions under Repository/Values/Content:

  • EmbeddingQuery: a value object representing a “semantic similarity” search request, encapsulating the text or vector to match against content embeddings.
  • EmbeddingQueryBuilder: a fluent builder for constructing EmbeddingQuery instances, enforcing required parameters (model, text/vector, threshold, etc.) and integrating with the Core query pipeline.
  • QueryValidatorInterface: validates that an EmbeddingQuery is well-formed (e.g., model exists, vector dimensions match configuration) before it reaches the search engine layer.

• Embedding contracts (in Contracts/Embedding):

  • EmbeddingConfigurationInterface
    Defines how embedding models are configured in the system (model name, dimensionality, provider reference, field suffix).
  • EmbeddingProviderInterface
    The runtime contract for any embedding engine—exposes a getEmbeddings(array $inputs): array method to generate vectors from text or other inputs.
  • EmbeddingProviderRegistryInterface
    A registry service that lists all available EmbeddingProviderInterface implementations, keyed by provider name.
  • EmbeddingProviderResolverInterface
    Resolves which EmbeddingProviderInterface should be used for a given EmbeddingConfigurationInterface (e.g., by model or provider alias).

• Search field type:

  • EmbeddingField and EmbeddingFieldFactory to define and instantiate custom search fields for embedding vectors.

This PR lays the groundwork for embedding-driven search across all supported engines.

For QA:

Documentation:

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[adamwojs]

declare(strict_types=1); is missing in multiple places as well as final modifier.

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed

Issues
2 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud