feat(Azure STT): add an option to use the lexical form of the transcription

[tarekasishm]

This PR introduces optional support for returning Azure Speech-to-Text results in lexical format.

✨ What’s new

• A new flag has been added to STTOptions to control whether the Azure STT plugin returns lexical or normalized text.
• The option defaults to false, so the current behavior remains unchanged.
• When enabled, the STT plugin will return Azure’s lexical form directly in the transcription result.

🔄 Backward compatibility

• This change is fully backward-compatible.
• Existing users will see no behavior change unless the new option is explicitly enabled.

🧩 Motivation

Some downstream use cases (e.g. custom NLU pipelines, post-processing, or domain-specific text handling) require access to the raw lexical transcription provided by Azure, rather than the normalized output. This change makes that possible without affecting existing integrations.

⚙️ Usage

• The new option is exposed as an additional field in STTOptions.
• Default behavior remains identical to the current implementation.
• Enabling the option switches the Azure STT response to lexical format.