feat: add CategoryImporter service and SeedCategoriesCommand for seeding category data

- Implemented CategoryImporter service to handle bulk export/import logic for categories.
- Created SeedCategoriesCommand to seed category tables from JSON files in data/seed/.
- Added validation and normalization for category data during import.
- Ensured proper error handling and user feedback during the seeding process.

config/services.yaml

@@ -20,6 +20,10 @@ services:
     App\:
         resource: '../src/'
 
+    App\Category\Command\SeedCategoriesCommand:
+        arguments:
+            $projectDir: '%kernel.project_dir%'
+
     App\Doctor\Controller\DoctorController:
         arguments:
             $projectDir: '%kernel.project_dir%'