Implement stock status check for EAPTS and EMR, and other changes on drug sync

[peacemanh]

• Added 'StockStatus' class to retrieve stock status from EAPTS using institution ID requested by EMR.
• Introduced endpoint to fetch stock status from EAPTS for a specific dispensing unit based on institution ID.
• Added route in 'main' to handle stock status check requests from EMR.
• Implemented a caching mechanism to reduce frequent API requests, minimizing server overhead and optimizing response times.