Fix for Prime Charges Visibility in Rate Calculator

🛠️ Issue
Earlier, the Rate Calculator was displaying Eshopbox Prime shipping charges
 even when the selected route (pickup and drop pincode combination) was not serviceable
.
This created confusion, as Prime charges were visible for routes where the service was unavailable.
✅ Fix
This issue has been resolved.
Eshopbox Prime charges will now be shown only when the selected route is serviceable.
This ensures accurate rate visibility and eliminates confusion during shipping cost estimation.