feat: rename 'fee' to 'unitPrice' across purchase components and models

- Updated form component to use 'unitPrice' instead of 'fee'.
- Adjusted product charge row form fields and templates to reflect the new naming.
- Modified receipt template and related components to utilize 'unitPrice'.
- Changed models and interfaces to replace 'fee' with 'unitPrice'.
- Updated supplier invoice and statistics components to align with the new naming convention.
- Added new API routes for dashboard and statistics modules.

src/app/modules/purchases/models/io.d.ts

@@ -17,7 +17,7 @@ export interface IPurchaseReceiptResponse extends IPurchaseReceiptRawResponse {}
 export interface IPurchaseItemRawResponse {
   id: number;
   count: number;
-  fee: number;
+  unitPrice: number;
   total: number;
   productId: number;
 }
@@ -34,7 +34,7 @@ export interface IPurchaseRequest {
 export interface IPurchaseItemRequest {
   productId: number;
   count: number;
-  fee: number;
+  unitPrice: number;
   total: number;
 }
 
@@ -51,7 +51,7 @@ export interface IPurchaseForm {
 export interface IPurchaseItemForm {
   product: Maybe<IProductResponse>;
   count: number;
-  fee: number;
+  unitPrice: number;
   total: number;
   description?: string;
 }