[Feature]: Sample for direct PDF ingestion & structured extraction with GPT-4.1 in Azure OpenAI Service

### Feature Description

Demonstrate how to use Azure OpenAI GPT-4.1 models to accept PDF files as the content input (based on the OpenAI file inputs feature ) and return a JSON structured output.

Purpose is to evaluate both the effectiveness of GPT-4.1, as well as the effectiveness of processing an entire document using the file input type.

### Use Case

With GPT-4.1 and direct file input:
- Engineering effort should drop to a single GPT call inside existing solutions.
- Newer GPT-4.1 models should enhance the accuracy and effectiveness of document data extraction solutions.

### Motivation

- Simplified solution – reduces the effort required to build document ingestion pipelines with GPT models