feat: add routes loader (#11592)

Fixes: FRMW-2919

This PR adds a new routes loader with a single responsibility of scanning the filesystem and collecting routes. Sorting of routes, merging middleware and registering them with express are going to separate implementations.

The new `RoutesLoader` class allows overriding routes as-well (not recommended though) and this is how routes are de-duplicated.

- When two routes for the exact route pattern/matcher are discovered, the routes loader will only keep the last one.

- Routes files can also override handlers for specific HTTP methods. For example, the original route file exported handlers for `GET` and `POST`, but the overriding one only defines `GET`. In that case, we will continue using the original implementation for the `POST` handler.

- If an overriding route file exports additional configuration like `export const AUTHENTICATION=false`, then this will only impact the handlers exported from this file and not the original handlers.

Routes sorting has been already been implemented in a separate PR and you can visualize it using this URL. https://routes-visualizer.fly.dev/

.changeset/strange-wasps-warn.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/framework": patch
+---
+
+feat: add routes loader

packages/core/framework/src/http/__fixtures__/routers-with-duplicates/admin/products/[id]/route.ts

@@ -0,0 +1,7 @@
+import { Request, Response } from "express"
+
+export async function GET(req: Request, res: Response): Promise<void> {
+  console.log("hello world")
+}
+
+export const AUTHENTICATE = false

packages/core/framework/src/http/__fixtures__/routers-with-duplicates/admin/products/route.ts

@@ -0,0 +1,11 @@
+import { Request, Response } from "express"
+
+export async function GET(req: Request, res: Response): Promise<void> {
+  console.log("hello world")
+}
+
+export async function POST(req: Request, res: Response): Promise<void> {
+  console.log("hello world")
+}
+
+export const AUTHENTICATE = false

packages/core/framework/src/http/__fixtures__/routers-with-duplicates/store/[customer_id]/orders/[order_id]/route.ts

@@ -0,0 +1,7 @@
+import { Request, Response } from "express"
+
+export function GET(req: Request, res: Response) {
+  /* const customerId = req.params.id;
+    const orderId = req.params.id;*/
+  res.send("list customers " + JSON.stringify(req.params))
+}