Implement data fetching module

[SaudAltamimi]

• Integrate with financial data API (e.g., Alpha Vantage, Yahoo Finance)
• Implement data caching mechanism
• Create data preprocessing functions

[SaudAltamimi]

Useful reference using yahoo finance:
https://medium.com/@amirarsalan.rajabi/gpt-investor-a-step-by-step-guide-to-use-openai-gpt-models-for-stock-analysis-9a7e6b7709b3

[AzizAlTayar]

Phenomenal, thank you!