what:
- adds variant inventory link management endpoints:
```
Link inventory item to variant
POST /products/:id/variants/:vid/inventory-items
Update variant's inventory item link
POST /products/:id/variants/:vid/inventory-items/:iid
Unlink variant's inventory item
DELETE /products/:id/variants/:vid/inventory-items/:iid
```
- a batch endpoint that does the above 3 across variants
```
POST /products/:id/variants/inventory-items
```
What
- Move sales channel integration tests from `/api` to `/http`
Deleted tests that do not belong in the suite:
- POST /admin/products/:id
- Mutation sales channels on products
- POST /admin/products
- Creating a product with a sales channel
- GET /admin/products
- Filtering products by sales channel
- Expanding with a sales channel
- GET /admin/orders
- Filtering orders by sales channel
- Expanding with a sales channel
- POST /admin/orders/:id/swaps
- Creating a swap with a sales channel
* chore: Move api key tests to http folder
* chore: Move some of the product category tests to http
* chore: Move collection tests to http
* chore: Remove unused database test
