feat: Implement notifications feed (#8224)

Designs: https://www.figma.com/design/z3aUuOVWUKmdHH0ofmMpEV/Web-app-3.0?node-id=10-50&t=9k6K9k7oJh5tIi09-0

![Screenshot 2024-07-22 at 17 02 10](https://github.com/user-attachments/assets/bc7da39f-8ddb-4f93-bf4e-884f063bc1c6)


CLOSES CC-219

packages/admin-next/dashboard/src/lib/client/client.ts

@@ -53,3 +53,8 @@ export const sdk = new Medusa({
     type: "session",
   },
 })
+
+// useful when you want to call the BE from the console and try things out quickly
+if (typeof window !== "undefined") {
+  ;(window as any).__sdk = sdk
+}