Enatega Admin Dashboard: When adding a Coupon, Discount field is allowing to enter more than 100%

### Describe the bug
When adding a coupon, the Discount field allows users to enter a value greater than 100%, which is invalid. This could lead to incorrect calculations and potential financial losses or Also display an error message that discount percentage should not exceed 100%.

### To Reproduce
Steps to reproduce the behavior:

1. Navigate to the Coupon Management section.
2. Click on Add New Coupon.
3. Enter a discount value greater than 100% (e.g., 150%).
4. Save the coupon, it will not save it so it should display an error message or restrict it to not enter amount greater than 100%.

### Expected behavior
The system should restrict the Discount field to a maximum of 100% and display a validation error if a higher value is entered.

Desktop (please complete the following information):

> OS: [e.g. Windows]
> Browser [e.g. Chrome]
> Version [e.g. Latest]

Start in the Admin Dashboard's Coupon Management section and reproduce the issue through the Add New Coupon form using a discount above 100%. Locate the Discount field validation, then verify that values over 100% are rejected or show an error stating that the discount percentage cannot exceed 100%.

Written by the indexing model from the issue text.