feat: enhance LLMClient with structured output capabilities

feat: enhance architecture and developer documentation for clarity and detail

Add cost tracking functionality across various components, including Executor, Planner, and FieldMapperAgent. Integrate CostTracker to monitor LLM and document intelligence costs, enhancing logging for cost-related metrics and providing detailed cost breakdowns in the user interface.

Update Azure OpenAI API version in settings and enhance logging in LLMClient for request URL

Add logging for settings initialization and update LLMClient to use settings for API version

Add logging for Azure OpenAI configuration in LLMClient

Update Dockerfile to use new app entry point and enhance requirements.txt with additional dependencies. Remove obsolete streamlit_app.py file.