feat: add discount functionality to sales and purchase transactions

- Introduced discount_type and discount fields in Bills and SalesReceipts controllers.
- Updated database migrations to include discount and discount_type in estimates and credit notes tables.
- Enhanced SaleReceipt and SaleEstimate models to support discount attributes.
- Implemented formatting for discount amounts in transformers and PDF templates.
- Updated email templates to display discount information.

This commit enhances the handling of discounts across various transaction types, improving the overall functionality and user experience.

shared/pdf-templates/src/components/EstimatePaperTemplate.tsx

@@ -48,6 +48,12 @@ export interface EstimatePaperTemplateProps extends PaperTemplateProps {
   showTotal?: boolean;
   totalLabel?: string;
 
+  // # Discount
+  discount?: string;
+  showDiscount?: boolean;
+  discountLabel?: string;
+
+  // # Subtotal
   subtotal?: string;
   showSubtotal?: boolean;
   subtotalLabel?: string;
@@ -101,6 +107,11 @@ export function EstimatePaperTemplate({
   totalLabel = 'Total',
   showTotal = true,
 
+  // # Discount
+  discount = '0.00',
+  discountLabel = 'Discount',
+  showDiscount = true,
+
   // # Subtotal
   subtotal = '1000/00',
   subtotalLabel = 'Subtotal',
@@ -202,8 +213,8 @@ export function EstimatePaperTemplate({
                     <Text>{data.item}</Text>
                     <Text
                       fontSize={'12px'}
-                    // className={Classes.TEXT_MUTED}
-                    // style={{ fontSize: 12 }}
+                      // className={Classes.TEXT_MUTED}
+                      // style={{ fontSize: 12 }}
                     >
                       {data.description}
                     </Text>
@@ -223,6 +234,12 @@ export function EstimatePaperTemplate({
                 amount={subtotal}
               />
             )}
+            {showDiscount && discount && (
+              <PaperTemplate.TotalLine
+                label={discountLabel}
+                amount={discount}
+              />
+            )}
             {showTotal && (
               <PaperTemplate.TotalLine label={totalLabel} amount={total} />
             )}