Add Natural Language Search feature

Problem/Motivation

As an Acquia DAM module user, I want natural language search results included automatically when searching for assets, so that search results are more relevant without requiring additional configuration.

Context

The DAM API v2 supports a include_natural_language_results query parameter on the asset search endpoint. When set to true, it includes natural language search results alongside standard results. Customers without NLS enabled in their DAM will not receive an error — the parameter is silently ignored.

API reference: https://docs.acquia.com/acquia-dam/api-v2#tag/Assets/operation/assetListBySearchQuery

Acceptance Criteria

• include_natural_language_results query parameter is always set to true on all asset search API calls — no user-facing toggle or configuration option
• No error or degraded behaviour for customers who do not have NLS enabled in their DAM
• NLS is not surfaced or called out in the UI or documentation (works silently for supported accounts)
• Code coverage updated to reflect the new parameter
• Documentation updated if needed