Added python program for tip calculator - Tipcalculator.py

[KYashnandan]

Problem

Inconsistent behavior in the tip calculation for user inputs leading to confusion and errors during execution.

Solution

Implemented input validation and improved output clarity to enhance user experience and prevent invalid data entry.

Changes Proposed

1.Added input validation to ensure positive numeric values for both tip percentage and bill amount.
2. Updated output messages to be clearer and more descriptive, removing formatted strings in favor of concatenation.
3. Created a separate function for displaying results to maintain code organization and readability.

Other Changes

1.Refactored exception handling to provide more informative error messages.
2.Improved function naming conventions for better code clarity.