fix: Tax region + rates clean up (#9279)

What
- Require `code` on Tax Rates
- Update dashboard to account for non-nullable code on Tax Rates

- Include `automatic_taxes` in API Route response

Closes CC-524 CC-525

integration-tests/http/__tests__/product/admin/product-import.spec.ts

@@ -2,7 +2,7 @@ import { IEventBusModuleService } from "@medusajs/types"
 import { CommonEvents, Modules } from "@medusajs/utils"
 import FormData from "form-data"
 import fs from "fs/promises"
-import { TestEventUtils, medusaIntegrationTestRunner } from "medusa-test-utils"
+import { medusaIntegrationTestRunner, TestEventUtils } from "medusa-test-utils"
 import path from "path"
 import {
   adminHeaders,