Update names of some SQL tables

[bglamadrid]

Tables mapped to the entities listed below are not correctly following naming conventions.

• ProductCategory - products_categories should be product_categories
• ProductImage - products_images should be product_images
• SellStatus - sales_statuses should be sell_statuses
• UserRole - app_users_roles should be app_user_roles
• UserRolePermission - app_users_roles_permissions should be app_user_role_permissions