[IMP] point_of_sale: Update ScaleScreen for automatic price update on tare change

[nesma-neha]

Description:

This PR simplifies weight and price management. It improves how weights and prices are displayed and adds automatic price adjustments based on tare weight changes.

Changes:

• Improved interface for easier weight management and price calculation.
• Updated the display of weight and price for better clarity.
• Added automatic price adjustment based on changes in the tare weight.

Task ID: 3984103

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