Feat(medusa, medusa-js, medusa-react): Include sales channels in related queries as an optional expand parameter (#1816)

**What**
- Add `transformQuery` to get endpoints for product, order and cart
  - ensure that the default relations (when getting a singular entity) includes sales channels when enabled
- Add `EmptyQueryParams` class in common types to prevent query parameters while using `transformQuery`
- update product-, order- and cartFactory to include sales channels if provided
- remove `packages/medusa/src/controllers/products/admin-list-products.ts`

**Testing** 
- expands sales channel for single order
- expands sales channels for orders with expand parameter 
- returns single product with sales channel 
- expands sales channels for products with expand parameter
- returns cart with sales channel for single cart

Fixes CORE-293

Co-authored-by: Sebastian Rindom <7554214+srindom@users.noreply.github.com>
Co-authored-by: Adrien de Peretti <25098370+adrien2p@users.noreply.github.com>

packages/medusa/jest.config.js

@@ -20,4 +20,5 @@ module.exports = {
   },
   testEnvironment: `node`,
   moduleFileExtensions: [`js`, `jsx`, `ts`, `tsx`, `json`],
+  "setupFilesAfterEnv": ["<rootDir>/setupTests.js"]
 }