add proxy endpoint for retrieveing the backpack (explorer) (#1259)

* add proxy endpoint for retrieveing the backpack (explorer)

* add suggested code review

Author: gonpombo8

packages/@dcl/sdk-commands/src/commands/start/server/endpoints.ts

@@ -137,6 +137,25 @@ export async function setupEcs6Endpoints(
     return res
   })
 
+  router.all('/explorer/:path+', async (ctx) => {
+    const u = new URL(ctx.url.toString())
+    u.host = catalystUrl.host
+    u.protocol = catalystUrl.protocol
+    u.port = catalystUrl.port
+    const req = await fetch(u.toString(), {
+      headers: { connection: 'close' },
+      method: ctx.request.method,
+      body: ctx.request.method === 'get' ? undefined : ctx.request.body
+    })
+
+    return {
+      headers: {
+        'content-type': req.headers.get('content-type') || 'application/json'
+      },
+      body: req.body
+    }
+  })
+
   serveStatic(components, workspace, router)
 
   // TODO: get workspace scenes & wearables...