Description:
Added new endpoint to update multiple package prices at once. This will save a lot of time for the product team when they need to adjust pricing for campaigns.

Changes:

• Added bulkUpdatePrices controller function in controllers/package.controller.ts
• Added route in routes/package.routes.ts
• Uses existing updatePackagePrice service method for each package

Testing:

• Tested with Postman using 3 packages
• All prices updated successfully
• Verified price history was created for each package

Related Ticket: FEAT-2345