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/shared/components/input/input.component.ts

@@ -45,6 +45,7 @@ export class InputComponent {
   @Input() showErrors = false;
   @Input() hint?: string;
   @Output() valueChange = new EventEmitter<string | number>();
+  @Output() blur = new EventEmitter<void>();
 
   onInput(ev: Event) {
     const v = (ev.target as HTMLInputElement).value;