fix: migrate segment subscribers + typescript support (#5904)

Fixes #6068.

**What**

- Uses new Subscriber API.
- Adds support for typescript files in Segment plugin.
- Adds a peerDependency on @medusajs/medusa for the version that introduced new Subscriber API.

packages/medusa-plugin-segment/src/utils/gather-swap-report.ts

@@ -0,0 +1,71 @@
+import { humanizeAmount } from "medusa-core-utils"
+
+export async function gatherSwapReport(
+  id,
+  { swapService, segmentService, lineItemService }
+) {
+  const swap = await swapService.retrieve(id, {
+    relations: [
+      "order",
+      "additional_items",
+      "additional_items.variant",
+      "return_order",
+      "return_order.items",
+      "return_order.shipping_method",
+    ],
+  })
+
+  const currency = swap.order.currency_code
+
+  const newItems = await Promise.all(
+    swap.additional_items.map(async (i) => {
+      const price = humanizeAmount(i.unit_price, currency)
+      const reporting_price = await segmentService.getReportingValue(
+        currency,
+        price
+      )
+
+      return {
+        name: i.title,
+        product_id: i.variant.product_id,
+        variant: i.variant.sku,
+        quantity: i.quantity,
+        price,
+        reporting_price,
+      }
+    })
+  )
+
+  const returnItems = await Promise.all(
+    swap.return_order.items.map(async (ri) => {
+      const i = await lineItemService.retrieve(ri.item_id, {
+        relations: ["variant"],
+      })
+      const price = humanizeAmount(i.unit_price, currency)
+      const reporting_price = await segmentService.getReportingValue(
+        currency,
+        price
+      )
+
+      return {
+        name: i.title,
+        product_id: i.variant.product_id,
+        variant: i.variant.sku,
+        quantity: ri.quantity,
+        price,
+        reporting_price,
+      }
+    })
+  )
+
+  return [
+    swap,
+    {
+      swap_id: swap.id,
+      order_id: swap.order_id,
+      new_items: newItems,
+      return_items: returnItems,
+      currency,
+    },
+  ]
+}