feat: Admin V2 API keys (#6883)

Add API key management UI for V2

This PR only adds publishable API key UI. Secret API key management will come in a follow-up PR.

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

@@ -30,7 +30,7 @@ export const GET = async (
 
   const [apiKey] = await remoteQuery(queryObject)
 
-  res.status(200).json({ apiKey })
+  res.status(200).json({ api_key: apiKey })
 }
 
 export const POST = async (