feat: add staff tax forms module with I-9 and W-4 forms

- Created staff_tax_forms_module.dart to manage tax forms feature.
- Implemented routes for TaxFormsPage, FormI9Page, and FormW4Page.
- Added mock repository for tax forms.
- Established necessary dependencies in pubspec.yaml.
- Exported module in staff_tax_forms.dart.

apps/mobile/packages/features/staff/profile/lib/src/presentation/navigation/profile_navigator.dart

@@ -38,7 +38,7 @@ extension ProfileNavigator on IModularNavigator {
 
   /// Navigates to the tax forms page.
   void pushTaxForms() {
-    pushNamed('/tax-forms');
+    pushNamed('../tax-forms/');
   }
 
   /// Navigates to Krow University.