feat(tax): migration file (#6523)

**What**
- Tax Module Migration file.
- Skeleton for API routes and integrations tests for tax API in v2

packages/medusa/src/api-v2/admin/tax-rates/[id]/route.ts

@@ -0,0 +1,26 @@
+import {
+  AuthenticatedMedusaRequest,
+  MedusaResponse,
+} from "../../../../types/routing"
+
+import { defaultAdminTaxRateFields } from "../query-config"
+import { remoteQueryObjectFromString } from "@medusajs/utils"
+
+export const GET = async (
+  req: AuthenticatedMedusaRequest,
+  res: MedusaResponse
+) => {
+  const remoteQuery = req.scope.resolve("remoteQuery")
+
+  const variables = { id: req.params.id }
+
+  const queryObject = remoteQueryObjectFromString({
+    entryPoint: "tax_rate",
+    variables,
+    fields: defaultAdminTaxRateFields,
+  })
+
+  const [taxRate] = await remoteQuery(queryObject)
+
+  res.status(200).json({ tax_rate: taxRate })
+}

packages/medusa/src/api-v2/admin/tax-rates/middlewares.ts

@@ -0,0 +1,25 @@
+import * as QueryConfig from "./query-config"
+
+import { AdminGetTaxRatesTaxRateParams } from "./validators"
+import { transformQuery } from "../../../api/middlewares"
+
+import { MiddlewareRoute } from "../../../loaders/helpers/routing/types"
+import { authenticate } from "../../../utils/authenticate-middleware"
+
+export const adminTaxRateRoutesMiddlewares: MiddlewareRoute[] = [
+  {
+    method: ["ALL"],
+    matcher: "/admin/tax-rates*",
+    middlewares: [authenticate("admin", ["bearer", "session", "api-key"])],
+  },
+  {
+    method: ["GET"],
+    matcher: "/admin/tax-rates/:id",
+    middlewares: [
+      transformQuery(
+        AdminGetTaxRatesTaxRateParams,
+        QueryConfig.retrieveTransformQueryConfig
+      ),
+    ],
+  },
+]

packages/medusa/src/api-v2/admin/tax-rates/query-config.ts

@@ -0,0 +1,26 @@
+export const defaultAdminTaxRateRelations = []
+export const allowedAdminTaxRateRelations = []
+export const defaultAdminTaxRateFields = [
+  "id",
+  "name",
+  "code",
+  "rate",
+  "tax_region_id",
+  "created_by",
+  "created_at",
+  "updated_at",
+  "deleted_at",
+  "metadata",
+]
+
+export const retrieveTransformQueryConfig = {
+  defaultFields: defaultAdminTaxRateFields,
+  defaultRelations: defaultAdminTaxRateRelations,
+  allowedRelations: allowedAdminTaxRateRelations,
+  isList: false,
+}
+
+export const listTransformQueryConfig = {
+  defaultLimit: 20,
+  isList: true,
+}

packages/medusa/src/api-v2/admin/tax-rates/validators.ts

@@ -0,0 +1,3 @@
+import { FindParams } from "../../../types/common"
+
+export class AdminGetTaxRatesTaxRateParams extends FindParams {}