feat(dashboard,core-flows,js-sdk,types,medusa): Add exchange UI + fixes (#8606)

what:

- adds exchange UI
- fixes bugs on core-flows and endpoints
- random set of tiny fixes


https://github.com/user-attachments/assets/b163b9c1-4475-4936-ae98-20795760cc55

packages/admin-next/dashboard/src/providers/router-provider/route-map.tsx

@@ -248,6 +248,11 @@ export const RouteMap: RouteObject[] = [
                     lazy: () =>
                       import("../../routes/orders/order-create-claim"),
                   },
+                  {
+                    path: "exchanges",
+                    lazy: () =>
+                      import("../../routes/orders/order-create-exchange"),
+                  },
                   {
                     path: "payments/:paymentId/refund",
                     lazy: () =>