feat(medusa): Add metadata to Product Category (#5599)

* ✨ feat(migrations): add metadata column to product_category table in database to store additional information about each product category

* ✨ feat(product-category.ts): add metadata field to ProductCategory model to store additional details
📝 docs(product-category.ts): add documentation for new metadata field in ProductCategory model

* ✨ feat(product-category.ts): add metadata field to ProductCategoryInput type to support additional data

* ✨ feat(ProductCategory.ts): add optional metadata field to ProductCategory model to store additional details

* ✨ feat(product-categories): add metadata field to product categories for additional information storage
📝 docs(product-categories): add documentation for new metadata field in product categories

* ✨ feat(product-categories): add 'metadata' field to default and allowed product category fields for enhanced data tracking

* ✨ feat(product-category.ts): add metadata support to product categories
🔧 refactor(product-category.ts): import setMetadata from utils to handle metadata setting in a more efficient way

* ✨ feat(models): add metadata field to AdminPostProductCategoriesCategoryReq and AdminPostProductCategoriesReq models to store additional information

* 📝 docs(api-reference): add metadata field to ProductCategory schema in both admin and store specs
🔧 fix(api-reference): make metadata field required in ProductCategory schema to ensure data consistency

* Create nine-fishes-matter.md

---------

Co-authored-by: Oli Juhl <59018053+olivermrbl@users.noreply.github.com>

www/apps/api-reference/specs/admin/components/schemas/ProductCategory.yaml

@@ -12,6 +12,7 @@ required:
   - id
   - is_active
   - is_internal
+  - metadata
   - mpath
   - name
   - parent_category_id
@@ -84,3 +85,13 @@ properties:
     description: The date with timezone at which the resource was updated.
     type: string
     format: date-time
+  metadata:
+    description: An optional key-value map with additional details
+    nullable: true
+    type: object
+    example:
+      car: white
+    externalDocs:
+      description: Learn about the metadata attribute, and how to delete and update it.
+      url: >-
+        https://docs.medusajs.com/development/entities/overview#metadata-attribute