feat(medusa-js, medusa-react, medusa): Prepare API for admin implementations (#3110)

********What********
Add `joinSalesChannels util to stock locations

Add the following endpoints to medusa-react
- inventory items
    - mutations
        - update
        - delete
        - update location level
        - delete location level
        - create location level
    - queries
        - list inventory items
        - get inventory item
        - list location levels
- Stock locations
    - mutations
        - create stock location
        - update stock location
        - delete stock location
    - queries
        - list stock locations
        - get stock locatoin
- Variants
    - queries
        - get inventory
- Reservations
    - mutations
        - create reservation
        - update reservation
        - delete reservation
    - queries
        - list reservations
        - get reservation
- sales channels 
  - mutations
    - associate location with sc
    - remove location association

**Why**
- Update clients to reflect new api endpoints in the core with inventory modules

Co-authored-by: Philip Korsholm <88927411+pKorsholm@users.noreply.github.com>

packages/medusa-react/test/hooks/admin/sales-channels/mutations.test.ts

@@ -97,15 +97,15 @@ describe("useAdminDeleteProductsFromSalesChannel hook", () => {
       { wrapper: createWrapper() }
     )
 
-    result.current.mutate({ product_ids: [
-      { id: productId }
-    ]})
+    result.current.mutate({ product_ids: [{ id: productId }] })
 
     await waitFor(() => result.current.isSuccess)
 
-    expect(result.current.data).toEqual(expect.objectContaining({
-      sales_channel: fixtures.get("sales_channel"),
-    }))
+    expect(result.current.data).toEqual(
+      expect.objectContaining({
+        sales_channel: fixtures.get("sales_channel"),
+      })
+    )
   })
 })
 
@@ -119,14 +119,14 @@ describe("useAdminAddProductsToSalesChannel hook", () => {
       { wrapper: createWrapper() }
     )
 
-    result.current.mutate({ product_ids: [
-      { id: productId }
-    ]})
+    result.current.mutate({ product_ids: [{ id: productId }] })
 
     await waitFor(() => result.current.isSuccess)
 
-    expect(result.current.data).toEqual(expect.objectContaining({
-      sales_channel: fixtures.get("sales_channel"),
-    }))
+    expect(result.current.data).toEqual(
+      expect.objectContaining({
+        sales_channel: fixtures.get("sales_channel"),
+      })
+    )
   })
 })